README revision 261194
1 2 SENDMAIL CONFIGURATION FILES 3 4This document describes the sendmail configuration files. It 5explains how to create a sendmail.cf file for use with sendmail. 6It also describes how to set options for sendmail which are explained 7in the Sendmail Installation and Operation guide (doc/op/op.me). 8 9To get started, you may want to look at tcpproto.mc (for TCP-only 10sites) and clientproto.mc (for clusters of clients using a single 11mail host), or the generic-*.mc files as operating system-specific 12examples. 13 14Table of Content: 15 16INTRODUCTION AND EXAMPLE 17A BRIEF INTRODUCTION TO M4 18FILE LOCATIONS 19OSTYPE 20DOMAINS 21MAILERS 22FEATURES 23HACKS 24SITE CONFIGURATION 25USING UUCP MAILERS 26TWEAKING RULESETS 27MASQUERADING AND RELAYING 28USING LDAP FOR ALIASES, MAPS, AND CLASSES 29LDAP ROUTING 30ANTI-SPAM CONFIGURATION CONTROL 31CONNECTION CONTROL 32STARTTLS 33SMTP AUTHENTICATION 34ADDING NEW MAILERS OR RULESETS 35ADDING NEW MAIL FILTERS 36QUEUE GROUP DEFINITIONS 37NON-SMTP BASED CONFIGURATIONS 38WHO AM I? 39ACCEPTING MAIL FOR MULTIPLE NAMES 40USING MAILERTABLES 41USING USERDB TO MAP FULL NAMES 42MISCELLANEOUS SPECIAL FEATURES 43SECURITY NOTES 44TWEAKING CONFIGURATION OPTIONS 45MESSAGE SUBMISSION PROGRAM 46FORMAT OF FILES AND MAPS 47DIRECTORY LAYOUT 48ADMINISTRATIVE DETAILS 49 50 51+--------------------------+ 52| INTRODUCTION AND EXAMPLE | 53+--------------------------+ 54 55Configuration files are contained in the subdirectory "cf", with a 56suffix ".mc". They must be run through "m4" to produce a ".cf" file. 57You must pre-load "cf.m4": 58 59 m4 ${CFDIR}/m4/cf.m4 config.mc > config.cf 60 61Alternatively, you can simply: 62 63 cd ${CFDIR}/cf 64 ./Build config.cf 65 66where ${CFDIR} is the root of the cf directory and config.mc is the 67name of your configuration file. If you are running a version of M4 68that understands the __file__ builtin (versions of GNU m4 >= 0.75 do 69this, but the versions distributed with 4.4BSD and derivatives do not) 70or the -I flag (ditto), then ${CFDIR} can be in an arbitrary directory. 71For "traditional" versions, ${CFDIR} ***MUST*** be "..", or you MUST 72use -D_CF_DIR_=/path/to/cf/dir/ -- note the trailing slash! For example: 73 74 m4 -D_CF_DIR_=${CFDIR}/ ${CFDIR}/m4/cf.m4 config.mc > config.cf 75 76Let's examine a typical .mc file: 77 78 divert(-1) 79 # 80 # Copyright (c) 1998-2005 Proofpoint, Inc. and its suppliers. 81 # All rights reserved. 82 # Copyright (c) 1983 Eric P. Allman. All rights reserved. 83 # Copyright (c) 1988, 1993 84 # The Regents of the University of California. All rights reserved. 85 # 86 # By using this file, you agree to the terms and conditions set 87 # forth in the LICENSE file which can be found at the top level of 88 # the sendmail distribution. 89 # 90 91 # 92 # This is a Berkeley-specific configuration file for HP-UX 9.x. 93 # It applies only to the Computer Science Division at Berkeley, 94 # and should not be used elsewhere. It is provided on the sendmail 95 # distribution as a sample only. To create your own configuration 96 # file, create an appropriate domain file in ../domain, change the 97 # `DOMAIN' macro below to reference that file, and copy the result 98 # to a name of your own choosing. 99 # 100 divert(0) 101 102The divert(-1) will delete the crud in the resulting output file. 103The copyright notice can be replaced by whatever your lawyers require; 104our lawyers require the one that is included in these files. A copyleft 105is a copyright by another name. The divert(0) restores regular output. 106 107 VERSIONID(`<SCCS or RCS version id>') 108 109VERSIONID is a macro that stuffs the version information into the 110resulting file. You could use SCCS, RCS, CVS, something else, or 111omit it completely. This is not the same as the version id included 112in SMTP greeting messages -- this is defined in m4/version.m4. 113 114 OSTYPE(`hpux9')dnl 115 116You must specify an OSTYPE to properly configure things such as the 117pathname of the help and status files, the flags needed for the local 118mailer, and other important things. If you omit it, you will get an 119error when you try to build the configuration. Look at the ostype 120directory for the list of known operating system types. 121 122 DOMAIN(`CS.Berkeley.EDU')dnl 123 124This example is specific to the Computer Science Division at Berkeley. 125You can use "DOMAIN(`generic')" to get a sufficiently bland definition 126that may well work for you, or you can create a customized domain 127definition appropriate for your environment. 128 129 MAILER(`local') 130 MAILER(`smtp') 131 132These describe the mailers used at the default CS site. The local 133mailer is always included automatically. Beware: MAILER declarations 134should only be followed by LOCAL_* sections. The general rules are 135that the order should be: 136 137 VERSIONID 138 OSTYPE 139 DOMAIN 140 FEATURE 141 local macro definitions 142 MAILER 143 LOCAL_CONFIG 144 LOCAL_RULE_* 145 LOCAL_RULESETS 146 147There are a few exceptions to this rule. Local macro definitions which 148influence a FEATURE() should be done before that feature. For example, 149a define(`PROCMAIL_MAILER_PATH', ...) should be done before 150FEATURE(`local_procmail'). 151 152******************************************************************* 153*** BE SURE YOU CUSTOMIZE THESE FILES! They have some *** 154*** Berkeley-specific assumptions built in, such as the name *** 155*** of their UUCP-relay. You'll want to create your own *** 156*** domain description, and use that in place of *** 157*** domain/Berkeley.EDU.m4. *** 158******************************************************************* 159 160 161+----------------------------+ 162| A BRIEF INTRODUCTION TO M4 | 163+----------------------------+ 164 165Sendmail uses the M4 macro processor to ``compile'' the configuration 166files. The most important thing to know is that M4 is stream-based, 167that is, it doesn't understand about lines. For this reason, in some 168places you may see the word ``dnl'', which stands for ``delete 169through newline''; essentially, it deletes all characters starting 170at the ``dnl'' up to and including the next newline character. In 171most cases sendmail uses this only to avoid lots of unnecessary 172blank lines in the output. 173 174Other important directives are define(A, B) which defines the macro 175``A'' to have value ``B''. Macros are expanded as they are read, so 176one normally quotes both values to prevent expansion. For example, 177 178 define(`SMART_HOST', `smart.foo.com') 179 180One word of warning: M4 macros are expanded even in lines that appear 181to be comments. For example, if you have 182 183 # See FEATURE(`foo') above 184 185it will not do what you expect, because the FEATURE(`foo') will be 186expanded. This also applies to 187 188 # And then define the $X macro to be the return address 189 190because ``define'' is an M4 keyword. If you want to use them, surround 191them with directed quotes, `like this'. 192 193Since m4 uses single quotes (opening "`" and closing "'") to quote 194arguments, those quotes can't be used in arguments. For example, 195it is not possible to define a rejection message containing a single 196quote. Usually there are simple workarounds by changing those 197messages; in the worst case it might be ok to change the value 198directly in the generated .cf file, which however is not advised. 199 200 201Notice: 202------- 203 204This package requires a post-V7 version of m4; if you are running the 2054.2bsd, SysV.2, or 7th Edition version. SunOS's /usr/5bin/m4 or 206BSD-Net/2's m4 both work. GNU m4 version 1.1 or later also works. 207Unfortunately, the M4 on BSDI 1.0 doesn't work -- you'll have to use a 208Net/2 or GNU version. GNU m4 is available from 209ftp://ftp.gnu.org/pub/gnu/m4/m4-1.4.tar.gz (check for the latest version). 210EXCEPTIONS: DEC's m4 on Digital UNIX 4.x is broken (3.x is fine). Use GNU 211m4 on this platform. 212 213 214+----------------+ 215| FILE LOCATIONS | 216+----------------+ 217 218sendmail 8.9 has introduced a new configuration directory for sendmail 219related files, /etc/mail. The new files available for sendmail 8.9 -- 220the class {R} /etc/mail/relay-domains and the access database 221/etc/mail/access -- take advantage of this new directory. Beginning with 2228.10, all files will use this directory by default (some options may be 223set by OSTYPE() files). This new directory should help to restore 224uniformity to sendmail's file locations. 225 226Below is a table of some of the common changes: 227 228Old filename New filename 229------------ ------------ 230/etc/bitdomain /etc/mail/bitdomain 231/etc/domaintable /etc/mail/domaintable 232/etc/genericstable /etc/mail/genericstable 233/etc/uudomain /etc/mail/uudomain 234/etc/virtusertable /etc/mail/virtusertable 235/etc/userdb /etc/mail/userdb 236 237/etc/aliases /etc/mail/aliases 238/etc/sendmail/aliases /etc/mail/aliases 239/etc/ucbmail/aliases /etc/mail/aliases 240/usr/adm/sendmail/aliases /etc/mail/aliases 241/usr/lib/aliases /etc/mail/aliases 242/usr/lib/mail/aliases /etc/mail/aliases 243/usr/ucblib/aliases /etc/mail/aliases 244 245/etc/sendmail.cw /etc/mail/local-host-names 246/etc/mail/sendmail.cw /etc/mail/local-host-names 247/etc/sendmail/sendmail.cw /etc/mail/local-host-names 248 249/etc/sendmail.ct /etc/mail/trusted-users 250 251/etc/sendmail.oE /etc/mail/error-header 252 253/etc/sendmail.hf /etc/mail/helpfile 254/etc/mail/sendmail.hf /etc/mail/helpfile 255/usr/ucblib/sendmail.hf /etc/mail/helpfile 256/etc/ucbmail/sendmail.hf /etc/mail/helpfile 257/usr/lib/sendmail.hf /etc/mail/helpfile 258/usr/share/lib/sendmail.hf /etc/mail/helpfile 259/usr/share/misc/sendmail.hf /etc/mail/helpfile 260/share/misc/sendmail.hf /etc/mail/helpfile 261 262/etc/service.switch /etc/mail/service.switch 263 264/etc/sendmail.st /etc/mail/statistics 265/etc/mail/sendmail.st /etc/mail/statistics 266/etc/mailer/sendmail.st /etc/mail/statistics 267/etc/sendmail/sendmail.st /etc/mail/statistics 268/usr/lib/sendmail.st /etc/mail/statistics 269/usr/ucblib/sendmail.st /etc/mail/statistics 270 271Note that all of these paths actually use a new m4 macro MAIL_SETTINGS_DIR 272to create the pathnames. The default value of this variable is 273`/etc/mail/'. If you set this macro to a different value, you MUST include 274a trailing slash. 275 276Notice: all filenames used in a .mc (or .cf) file should be absolute 277(starting at the root, i.e., with '/'). Relative filenames most 278likely cause surprises during operations (unless otherwise noted). 279 280 281+--------+ 282| OSTYPE | 283+--------+ 284 285You MUST define an operating system environment, or the configuration 286file build will puke. There are several environments available; look 287at the "ostype" directory for the current list. This macro changes 288things like the location of the alias file and queue directory. Some 289of these files are identical to one another. 290 291It is IMPERATIVE that the OSTYPE occur before any MAILER definitions. 292In general, the OSTYPE macro should go immediately after any version 293information, and MAILER definitions should always go last. 294 295Operating system definitions are usually easy to write. They may define 296the following variables (everything defaults, so an ostype file may be 297empty). Unfortunately, the list of configuration-supported systems is 298not as broad as the list of source-supported systems, since many of 299the source contributors do not include corresponding ostype files. 300 301ALIAS_FILE [/etc/mail/aliases] The location of the text version 302 of the alias file(s). It can be a comma-separated 303 list of names (but be sure you quote values with 304 commas in them -- for example, use 305 define(`ALIAS_FILE', `a,b') 306 to get "a" and "b" both listed as alias files; 307 otherwise the define() primitive only sees "a"). 308HELP_FILE [/etc/mail/helpfile] The name of the file 309 containing information printed in response to 310 the SMTP HELP command. 311QUEUE_DIR [/var/spool/mqueue] The directory containing 312 queue files. To use multiple queues, supply 313 a value ending with an asterisk. For 314 example, /var/spool/mqueue/qd* will use all of the 315 directories or symbolic links to directories 316 beginning with 'qd' in /var/spool/mqueue as queue 317 directories. The names 'qf', 'df', and 'xf' are 318 reserved as specific subdirectories for the 319 corresponding queue file types as explained in 320 doc/op/op.me. See also QUEUE GROUP DEFINITIONS. 321MSP_QUEUE_DIR [/var/spool/clientmqueue] The directory containing 322 queue files for the MSP (Mail Submission Program, 323 see sendmail/SECURITY). 324STATUS_FILE [/etc/mail/statistics] The file containing status 325 information. 326LOCAL_MAILER_PATH [/bin/mail] The program used to deliver local mail. 327LOCAL_MAILER_FLAGS [Prmn9] The flags used by the local mailer. The 328 flags lsDFMAw5:/|@q are always included. 329LOCAL_MAILER_ARGS [mail -d $u] The arguments passed to deliver local 330 mail. 331LOCAL_MAILER_MAX [undefined] If defined, the maximum size of local 332 mail that you are willing to accept. 333LOCAL_MAILER_MAXMSGS [undefined] If defined, the maximum number of 334 messages to deliver in a single connection. Only 335 useful for LMTP local mailers. 336LOCAL_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 337 that ARRIVE from an address that resolves to the 338 local mailer and which are converted to MIME will be 339 labeled with this character set. 340LOCAL_MAILER_EOL [undefined] If defined, the string to use as the 341 end of line for the local mailer. 342LOCAL_MAILER_DSN_DIAGNOSTIC_CODE 343 [X-Unix] The DSN Diagnostic-Code value for the 344 local mailer. This should be changed with care. 345LOCAL_SHELL_PATH [/bin/sh] The shell used to deliver piped email. 346LOCAL_SHELL_FLAGS [eu9] The flags used by the shell mailer. The 347 flags lsDFM are always included. 348LOCAL_SHELL_ARGS [sh -c $u] The arguments passed to deliver "prog" 349 mail. 350LOCAL_SHELL_DIR [$z:/] The directory search path in which the 351 shell should run. 352LOCAL_MAILER_QGRP [undefined] The queue group for the local mailer. 353USENET_MAILER_PATH [/usr/lib/news/inews] The name of the program 354 used to submit news. 355USENET_MAILER_FLAGS [rsDFMmn] The mailer flags for the usenet mailer. 356USENET_MAILER_ARGS [-m -h -n] The command line arguments for the 357 usenet mailer. NOTE: Some versions of inews 358 (such as those shipped with newer versions of INN) 359 use different flags. Double check the defaults 360 against the inews man page. 361USENET_MAILER_MAX [undefined] The maximum size of messages that will 362 be accepted by the usenet mailer. 363USENET_MAILER_QGRP [undefined] The queue group for the usenet mailer. 364SMTP_MAILER_FLAGS [undefined] Flags added to SMTP mailer. Default 365 flags are `mDFMuX' for all SMTP-based mailers; the 366 "esmtp" mailer adds `a'; "smtp8" adds `8'; and 367 "dsmtp" adds `%'. 368RELAY_MAILER_FLAGS [undefined] Flags added to the relay mailer. Default 369 flags are `mDFMuX' for all SMTP-based mailers; the 370 relay mailer adds `a8'. If this is not defined, 371 then SMTP_MAILER_FLAGS is used. 372SMTP_MAILER_MAX [undefined] The maximum size of messages that will 373 be transported using the smtp, smtp8, esmtp, or dsmtp 374 mailers. 375SMTP_MAILER_MAXMSGS [undefined] If defined, the maximum number of 376 messages to deliver in a single connection for the 377 smtp, smtp8, esmtp, or dsmtp mailers. 378SMTP_MAILER_MAXRCPTS [undefined] If defined, the maximum number of 379 recipients to deliver in a single connection for the 380 smtp, smtp8, esmtp, or dsmtp mailers. 381SMTP_MAILER_ARGS [TCP $h] The arguments passed to the smtp mailer. 382 About the only reason you would want to change this 383 would be to change the default port. 384ESMTP_MAILER_ARGS [TCP $h] The arguments passed to the esmtp mailer. 385SMTP8_MAILER_ARGS [TCP $h] The arguments passed to the smtp8 mailer. 386DSMTP_MAILER_ARGS [TCP $h] The arguments passed to the dsmtp mailer. 387RELAY_MAILER_ARGS [TCP $h] The arguments passed to the relay mailer. 388SMTP_MAILER_QGRP [undefined] The queue group for the smtp mailer. 389ESMTP_MAILER_QGRP [undefined] The queue group for the esmtp mailer. 390SMTP8_MAILER_QGRP [undefined] The queue group for the smtp8 mailer. 391DSMTP_MAILER_QGRP [undefined] The queue group for the dsmtp mailer. 392RELAY_MAILER_QGRP [undefined] The queue group for the relay mailer. 393RELAY_MAILER_MAXMSGS [undefined] If defined, the maximum number of 394 messages to deliver in a single connection for the 395 relay mailer. 396SMTP_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 397 that ARRIVE from an address that resolves to one of 398 the SMTP mailers and which are converted to MIME will 399 be labeled with this character set. 400SMTP_MAILER_LL [990] The maximum line length for SMTP mailers 401 (except the relay mailer). 402RELAY_MAILER_LL [2040] The maximum line length for the relay mailer. 403UUCP_MAILER_PATH [/usr/bin/uux] The program used to send UUCP mail. 404UUCP_MAILER_FLAGS [undefined] Flags added to UUCP mailer. Default 405 flags are `DFMhuU' (and `m' for uucp-new mailer, 406 minus `U' for uucp-dom mailer). 407UUCP_MAILER_ARGS [uux - -r -z -a$g -gC $h!rmail ($u)] The arguments 408 passed to the UUCP mailer. 409UUCP_MAILER_MAX [100000] The maximum size message accepted for 410 transmission by the UUCP mailers. 411UUCP_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 412 that ARRIVE from an address that resolves to one of 413 the UUCP mailers and which are converted to MIME will 414 be labeled with this character set. 415UUCP_MAILER_QGRP [undefined] The queue group for the UUCP mailers. 416FAX_MAILER_PATH [/usr/local/lib/fax/mailfax] The program used to 417 submit FAX messages. 418FAX_MAILER_ARGS [mailfax $u $h $f] The arguments passed to the FAX 419 mailer. 420FAX_MAILER_MAX [100000] The maximum size message accepted for 421 transmission by FAX. 422POP_MAILER_PATH [/usr/lib/mh/spop] The pathname of the POP mailer. 423POP_MAILER_FLAGS [Penu] Flags added to POP mailer. Flags lsDFMq 424 are always added. 425POP_MAILER_ARGS [pop $u] The arguments passed to the POP mailer. 426POP_MAILER_QGRP [undefined] The queue group for the pop mailer. 427PROCMAIL_MAILER_PATH [/usr/local/bin/procmail] The path to the procmail 428 program. This is also used by 429 FEATURE(`local_procmail'). 430PROCMAIL_MAILER_FLAGS [SPhnu9] Flags added to Procmail mailer. Flags 431 DFM are always set. This is NOT used by 432 FEATURE(`local_procmail'); tweak LOCAL_MAILER_FLAGS 433 instead. 434PROCMAIL_MAILER_ARGS [procmail -Y -m $h $f $u] The arguments passed to 435 the Procmail mailer. This is NOT used by 436 FEATURE(`local_procmail'); tweak LOCAL_MAILER_ARGS 437 instead. 438PROCMAIL_MAILER_MAX [undefined] If set, the maximum size message that 439 will be accepted by the procmail mailer. 440PROCMAIL_MAILER_QGRP [undefined] The queue group for the procmail mailer. 441MAIL11_MAILER_PATH [/usr/etc/mail11] The path to the mail11 mailer. 442MAIL11_MAILER_FLAGS [nsFx] Flags for the mail11 mailer. 443MAIL11_MAILER_ARGS [mail11 $g $x $h $u] Arguments passed to the mail11 444 mailer. 445MAIL11_MAILER_QGRP [undefined] The queue group for the mail11 mailer. 446PH_MAILER_PATH [/usr/local/etc/phquery] The path to the phquery 447 program. 448PH_MAILER_FLAGS [ehmu] Flags for the phquery mailer. Flags nrDFM 449 are always set. 450PH_MAILER_ARGS [phquery -- $u] -- arguments to the phquery mailer. 451PH_MAILER_QGRP [undefined] The queue group for the ph mailer. 452CYRUS_MAILER_FLAGS [Ah5@/:|] The flags used by the cyrus mailer. The 453 flags lsDFMnPq are always included. 454CYRUS_MAILER_PATH [/usr/cyrus/bin/deliver] The program used to deliver 455 cyrus mail. 456CYRUS_MAILER_ARGS [deliver -e -m $h -- $u] The arguments passed 457 to deliver cyrus mail. 458CYRUS_MAILER_MAX [undefined] If set, the maximum size message that 459 will be accepted by the cyrus mailer. 460CYRUS_MAILER_USER [cyrus:mail] The user and group to become when 461 running the cyrus mailer. 462CYRUS_MAILER_QGRP [undefined] The queue group for the cyrus mailer. 463CYRUS_BB_MAILER_FLAGS [u] The flags used by the cyrusbb mailer. 464 The flags lsDFMnP are always included. 465CYRUS_BB_MAILER_ARGS [deliver -e -m $u] The arguments passed 466 to deliver cyrusbb mail. 467CYRUSV2_MAILER_FLAGS [A@/:|m] The flags used by the cyrusv2 mailer. The 468 flags lsDFMnqXz are always included. 469CYRUSV2_MAILER_MAXMSGS [undefined] If defined, the maximum number of 470 messages to deliver in a single connection for the 471 cyrusv2 mailer. 472CYRUSV2_MAILER_MAXRCPTS [undefined] If defined, the maximum number of 473 recipients to deliver in a single connection for the 474 cyrusv2 mailer. 475CYRUSV2_MAILER_ARGS [FILE /var/imap/socket/lmtp] The arguments passed 476 to the cyrusv2 mailer. This can be used to 477 change the name of the Unix domain socket, or 478 to switch to delivery via TCP (e.g., `TCP $h lmtp') 479CYRUSV2_MAILER_QGRP [undefined] The queue group for the cyrusv2 mailer. 480CYRUSV2_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 481 that ARRIVE from an address that resolves to one the 482 Cyrus mailer and which are converted to MIME will 483 be labeled with this character set. 484confEBINDIR [/usr/libexec] The directory for executables. 485 Currently used for FEATURE(`local_lmtp') and 486 FEATURE(`smrsh'). 487QPAGE_MAILER_FLAGS [mDFMs] The flags used by the qpage mailer. 488QPAGE_MAILER_PATH [/usr/local/bin/qpage] The program used to deliver 489 qpage mail. 490QPAGE_MAILER_ARGS [qpage -l0 -m -P$u] The arguments passed 491 to deliver qpage mail. 492QPAGE_MAILER_MAX [4096] If set, the maximum size message that 493 will be accepted by the qpage mailer. 494QPAGE_MAILER_QGRP [undefined] The queue group for the qpage mailer. 495LOCAL_PROG_QGRP [undefined] The queue group for the prog mailer. 496 497Note: to tweak Name_MAILER_FLAGS use the macro MODIFY_MAILER_FLAGS: 498MODIFY_MAILER_FLAGS(`Name', `change') where Name is the first part 499of the macro Name_MAILER_FLAGS (note: that means Name is entirely in 500upper case) and change can be: flags that should be used directly 501(thus overriding the default value), or if it starts with `+' (`-') 502then those flags are added to (removed from) the default value. 503Example: 504 505 MODIFY_MAILER_FLAGS(`LOCAL', `+e') 506 507will add the flag `e' to LOCAL_MAILER_FLAGS. Notice: there are 508several smtp mailers all of which are manipulated individually. 509See the section MAILERS for the available mailer names. 510WARNING: The FEATUREs local_lmtp and local_procmail set LOCAL_MAILER_FLAGS 511unconditionally, i.e., without respecting any definitions in an 512OSTYPE setting. 513 514 515+---------+ 516| DOMAINS | 517+---------+ 518 519You will probably want to collect domain-dependent defines into one 520file, referenced by the DOMAIN macro. For example, the Berkeley 521domain file includes definitions for several internal distinguished 522hosts: 523 524UUCP_RELAY The host that will accept UUCP-addressed email. 525 If not defined, all UUCP sites must be directly 526 connected. 527BITNET_RELAY The host that will accept BITNET-addressed email. 528 If not defined, the .BITNET pseudo-domain won't work. 529DECNET_RELAY The host that will accept DECNET-addressed email. 530 If not defined, the .DECNET pseudo-domain and addresses 531 of the form node::user will not work. 532FAX_RELAY The host that will accept mail to the .FAX pseudo-domain. 533 The "fax" mailer overrides this value. 534LOCAL_RELAY The site that will handle unqualified names -- that 535 is, names without an @domain extension. 536 Normally MAIL_HUB is preferred for this function. 537 LOCAL_RELAY is mostly useful in conjunction with 538 FEATURE(`stickyhost') -- see the discussion of 539 stickyhost below. If not set, they are assumed to 540 belong on this machine. This allows you to have a 541 central site to store a company- or department-wide 542 alias database. This only works at small sites, 543 and only with some user agents. 544LUSER_RELAY The site that will handle lusers -- that is, apparently 545 local names that aren't local accounts or aliases. To 546 specify a local user instead of a site, set this to 547 ``local:username''. 548 549Any of these can be either ``mailer:hostname'' (in which case the 550mailer is the internal mailer name, such as ``uucp-new'' and the hostname 551is the name of the host as appropriate for that mailer) or just a 552``hostname'', in which case a default mailer type (usually ``relay'', 553a variant on SMTP) is used. WARNING: if you have a wildcard MX 554record matching your domain, you probably want to define these to 555have a trailing dot so that you won't get the mail diverted back 556to yourself. 557 558The domain file can also be used to define a domain name, if needed 559(using "DD<domain>") and set certain site-wide features. If all hosts 560at your site masquerade behind one email name, you could also use 561MASQUERADE_AS here. 562 563You do not have to define a domain -- in particular, if you are a 564single machine sitting off somewhere, it is probably more work than 565it's worth. This is just a mechanism for combining "domain dependent 566knowledge" into one place. 567 568 569+---------+ 570| MAILERS | 571+---------+ 572 573There are fewer mailers supported in this version than the previous 574version, owing mostly to a simpler world. As a general rule, put the 575MAILER definitions last in your .mc file. 576 577local The local and prog mailers. You will almost always 578 need these; the only exception is if you relay ALL 579 your mail to another site. This mailer is included 580 automatically. 581 582smtp The Simple Mail Transport Protocol mailer. This does 583 not hide hosts behind a gateway or another other 584 such hack; it assumes a world where everyone is 585 running the name server. This file actually defines 586 five mailers: "smtp" for regular (old-style) SMTP to 587 other servers, "esmtp" for extended SMTP to other 588 servers, "smtp8" to do SMTP to other servers without 589 converting 8-bit data to MIME (essentially, this is 590 your statement that you know the other end is 8-bit 591 clean even if it doesn't say so), "dsmtp" to do on 592 demand delivery, and "relay" for transmission to the 593 RELAY_HOST, LUSER_RELAY, or MAIL_HUB. 594 595uucp The UNIX-to-UNIX Copy Program mailer. Actually, this 596 defines two mailers, "uucp-old" (a.k.a. "uucp") and 597 "uucp-new" (a.k.a. "suucp"). The latter is for when you 598 know that the UUCP mailer at the other end can handle 599 multiple recipients in one transfer. If the smtp mailer 600 is included in your configuration, two other mailers 601 ("uucp-dom" and "uucp-uudom") are also defined [warning: you 602 MUST specify MAILER(`smtp') before MAILER(`uucp')]. When you 603 include the uucp mailer, sendmail looks for all names in 604 class {U} and sends them to the uucp-old mailer; all 605 names in class {Y} are sent to uucp-new; and all 606 names in class {Z} are sent to uucp-uudom. Note that 607 this is a function of what version of rmail runs on 608 the receiving end, and hence may be out of your control. 609 See the section below describing UUCP mailers in more 610 detail. 611 612usenet Usenet (network news) delivery. If this is specified, 613 an extra rule is added to ruleset 0 that forwards all 614 local email for users named ``group.usenet'' to the 615 ``inews'' program. Note that this works for all groups, 616 and may be considered a security problem. 617 618fax Facsimile transmission. This is experimental and based 619 on Sam Leffler's HylaFAX software. For more information, 620 see http://www.hylafax.org/. 621 622pop Post Office Protocol. 623 624procmail An interface to procmail (does not come with sendmail). 625 This is designed to be used in mailertables. For example, 626 a common question is "how do I forward all mail for a given 627 domain to a single person?". If you have this mailer 628 defined, you could set up a mailertable reading: 629 630 host.com procmail:/etc/procmailrcs/host.com 631 632 with the file /etc/procmailrcs/host.com reading: 633 634 :0 # forward mail for host.com 635 ! -oi -f $1 person@other.host 636 637 This would arrange for (anything)@host.com to be sent 638 to person@other.host. In a procmail script, $1 is the 639 name of the sender and $2 is the name of the recipient. 640 If you use this with FEATURE(`local_procmail'), the FEATURE 641 should be listed first. 642 643 Of course there are other ways to solve this particular 644 problem, e.g., a catch-all entry in a virtusertable. 645 646mail11 The DECnet mail11 mailer, useful only if you have the mail11 647 program from gatekeeper.dec.com:/pub/DEC/gwtools (and 648 DECnet, of course). This is for Phase IV DECnet support; 649 if you have Phase V at your site you may have additional 650 problems. 651 652phquery The phquery program. This is somewhat counterintuitively 653 referenced as the "ph" mailer internally. It can be used 654 to do CCSO name server lookups. The phquery program, which 655 this mailer uses, is distributed with the ph client. 656 657cyrus The cyrus and cyrusbb mailers. The cyrus mailer delivers to 658 a local cyrus user. this mailer can make use of the 659 "user+detail@local.host" syntax (see 660 FEATURE(`preserve_local_plus_detail')); it will deliver the 661 mail to the user's "detail" mailbox if the mailbox's ACL 662 permits. The cyrusbb mailer delivers to a system-wide 663 cyrus mailbox if the mailbox's ACL permits. The cyrus 664 mailer must be defined after the local mailer. 665 666cyrusv2 The mailer for Cyrus v2.x. The cyrusv2 mailer delivers to 667 local cyrus users via LMTP. This mailer can make use of the 668 "user+detail@local.host" syntax (see 669 FEATURE(`preserve_local_plus_detail')); it will deliver the 670 mail to the user's "detail" mailbox if the mailbox's ACL 671 permits. The cyrusv2 mailer must be defined after the 672 local mailer. 673 674qpage A mailer for QuickPage, a pager interface. See 675 http://www.qpage.org/ for further information. 676 677The local mailer accepts addresses of the form "user+detail", where 678the "+detail" is not used for mailbox matching but is available 679to certain local mail programs (in particular, see 680FEATURE(`local_procmail')). For example, "eric", "eric+sendmail", and 681"eric+sww" all indicate the same user, but additional arguments <null>, 682"sendmail", and "sww" may be provided for use in sorting mail. 683 684 685+----------+ 686| FEATURES | 687+----------+ 688 689Special features can be requested using the "FEATURE" macro. For 690example, the .mc line: 691 692 FEATURE(`use_cw_file') 693 694tells sendmail that you want to have it read an /etc/mail/local-host-names 695file to get values for class {w}. A FEATURE may contain up to 9 696optional parameters -- for example: 697 698 FEATURE(`mailertable', `dbm /usr/lib/mailertable') 699 700The default database map type for the table features can be set with 701 702 define(`DATABASE_MAP_TYPE', `dbm') 703 704which would set it to use ndbm databases. The default is the Berkeley DB 705hash database format. Note that you must still declare a database map type 706if you specify an argument to a FEATURE. DATABASE_MAP_TYPE is only used 707if no argument is given for the FEATURE. It must be specified before any 708feature that uses a map. 709 710Also, features which can take a map definition as an argument can also take 711the special keyword `LDAP'. If that keyword is used, the map will use the 712LDAP definition described in the ``USING LDAP FOR ALIASES, MAPS, AND 713CLASSES'' section below. 714 715Available features are: 716 717use_cw_file Read the file /etc/mail/local-host-names file to get 718 alternate names for this host. This might be used if you 719 were on a host that MXed for a dynamic set of other hosts. 720 If the set is static, just including the line "Cw<name1> 721 <name2> ..." (where the names are fully qualified domain 722 names) is probably superior. The actual filename can be 723 overridden by redefining confCW_FILE. 724 725use_ct_file Read the file /etc/mail/trusted-users file to get the 726 names of users that will be ``trusted'', that is, able to 727 set their envelope from address using -f without generating 728 a warning message. The actual filename can be overridden 729 by redefining confCT_FILE. 730 731redirect Reject all mail addressed to "address.REDIRECT" with 732 a ``551 User has moved; please try <address>'' message. 733 If this is set, you can alias people who have left 734 to their new address with ".REDIRECT" appended. 735 736nouucp Don't route UUCP addresses. This feature takes one 737 parameter: 738 `reject': reject addresses which have "!" in the local 739 part unless it originates from a system 740 that is allowed to relay. 741 `nospecial': don't do anything special with "!". 742 Warnings: 1. See the notice in the anti-spam section. 743 2. don't remove "!" from OperatorChars if `reject' is 744 given as parameter. 745 746nocanonify Don't pass addresses to $[ ... $] for canonification 747 by default, i.e., host/domain names are considered canonical, 748 except for unqualified names, which must not be used in this 749 mode (violation of the standard). It can be changed by 750 setting the DaemonPortOptions modifiers (M=). That is, 751 FEATURE(`nocanonify') will be overridden by setting the 752 'c' flag. Conversely, if FEATURE(`nocanonify') is not used, 753 it can be emulated by setting the 'C' flag 754 (DaemonPortOptions=Modifiers=C). This would generally only 755 be used by sites that only act as mail gateways or which have 756 user agents that do full canonification themselves. You may 757 also want to use 758 "define(`confBIND_OPTS', `-DNSRCH -DEFNAMES')" to turn off 759 the usual resolver options that do a similar thing. 760 761 An exception list for FEATURE(`nocanonify') can be 762 specified with CANONIFY_DOMAIN or CANONIFY_DOMAIN_FILE, 763 i.e., a list of domains which are nevertheless passed to 764 $[ ... $] for canonification. This is useful to turn on 765 canonification for local domains, e.g., use 766 CANONIFY_DOMAIN(`my.domain my') to canonify addresses 767 which end in "my.domain" or "my". 768 Another way to require canonification in the local 769 domain is CANONIFY_DOMAIN(`$=m'). 770 771 A trailing dot is added to addresses with more than 772 one component in it such that other features which 773 expect a trailing dot (e.g., virtusertable) will 774 still work. 775 776 If `canonify_hosts' is specified as parameter, i.e., 777 FEATURE(`nocanonify', `canonify_hosts'), then 778 addresses which have only a hostname, e.g., 779 <user@host>, will be canonified (and hopefully fully 780 qualified), too. 781 782stickyhost This feature is sometimes used with LOCAL_RELAY, 783 although it can be used for a different effect with 784 MAIL_HUB. 785 786 When used without MAIL_HUB, email sent to 787 "user@local.host" are marked as "sticky" -- that 788 is, the local addresses aren't matched against UDB, 789 don't go through ruleset 5, and are not forwarded to 790 the LOCAL_RELAY (if defined). 791 792 With MAIL_HUB, mail addressed to "user@local.host" 793 is forwarded to the mail hub, with the envelope 794 address still remaining "user@local.host". 795 Without stickyhost, the envelope would be changed 796 to "user@mail_hub", in order to protect against 797 mailing loops. 798 799mailertable Include a "mailer table" which can be used to override 800 routing for particular domains (which are not in class {w}, 801 i.e. local host names). The argument of the FEATURE may be 802 the key definition. If none is specified, the definition 803 used is: 804 805 hash /etc/mail/mailertable 806 807 Keys in this database are fully qualified domain names 808 or partial domains preceded by a dot -- for example, 809 "vangogh.CS.Berkeley.EDU" or ".CS.Berkeley.EDU". As a 810 special case of the latter, "." matches any domain not 811 covered by other keys. Values must be of the form: 812 mailer:domain 813 where "mailer" is the internal mailer name, and "domain" 814 is where to send the message. These maps are not 815 reflected into the message header. As a special case, 816 the forms: 817 local:user 818 will forward to the indicated user using the local mailer, 819 local: 820 will forward to the original user in the e-mail address 821 using the local mailer, and 822 error:code message 823 error:D.S.N:code message 824 will give an error message with the indicated SMTP reply 825 code and message, where D.S.N is an RFC 1893 compliant 826 error code. 827 828domaintable Include a "domain table" which can be used to provide 829 domain name mapping. Use of this should really be 830 limited to your own domains. It may be useful if you 831 change names (e.g., your company changes names from 832 oldname.com to newname.com). The argument of the 833 FEATURE may be the key definition. If none is specified, 834 the definition used is: 835 836 hash /etc/mail/domaintable 837 838 The key in this table is the domain name; the value is 839 the new (fully qualified) domain. Anything in the 840 domaintable is reflected into headers; that is, this 841 is done in ruleset 3. 842 843bitdomain Look up bitnet hosts in a table to try to turn them into 844 internet addresses. The table can be built using the 845 bitdomain program contributed by John Gardiner Myers. 846 The argument of the FEATURE may be the key definition; if 847 none is specified, the definition used is: 848 849 hash /etc/mail/bitdomain 850 851 Keys are the bitnet hostname; values are the corresponding 852 internet hostname. 853 854uucpdomain Similar feature for UUCP hosts. The default map definition 855 is: 856 857 hash /etc/mail/uudomain 858 859 At the moment there is no automagic tool to build this 860 database. 861 862always_add_domain 863 Include the local host domain even on locally delivered 864 mail. Normally it is not added on unqualified names. 865 However, if you use a shared message store but do not use 866 the same user name space everywhere, you may need the host 867 name on local names. An optional argument specifies 868 another domain to be added than the local. 869 870allmasquerade If masquerading is enabled (using MASQUERADE_AS), this 871 feature will cause recipient addresses to also masquerade 872 as being from the masquerade host. Normally they get 873 the local hostname. Although this may be right for 874 ordinary users, it can break local aliases. For example, 875 if you send to "localalias", the originating sendmail will 876 find that alias and send to all members, but send the 877 message with "To: localalias@masqueradehost". Since that 878 alias likely does not exist, replies will fail. Use this 879 feature ONLY if you can guarantee that the ENTIRE 880 namespace on your masquerade host supersets all the 881 local entries. 882 883limited_masquerade 884 Normally, any hosts listed in class {w} are masqueraded. If 885 this feature is given, only the hosts listed in class {M} (see 886 below: MASQUERADE_DOMAIN) are masqueraded. This is useful 887 if you have several domains with disjoint namespaces hosted 888 on the same machine. 889 890masquerade_entire_domain 891 If masquerading is enabled (using MASQUERADE_AS) and 892 MASQUERADE_DOMAIN (see below) is set, this feature will 893 cause addresses to be rewritten such that the masquerading 894 domains are actually entire domains to be hidden. All 895 hosts within the masquerading domains will be rewritten 896 to the masquerade name (used in MASQUERADE_AS). For example, 897 if you have: 898 899 MASQUERADE_AS(`masq.com') 900 MASQUERADE_DOMAIN(`foo.org') 901 MASQUERADE_DOMAIN(`bar.com') 902 903 then *foo.org and *bar.com are converted to masq.com. Without 904 this feature, only foo.org and bar.com are masqueraded. 905 906 NOTE: only domains within your jurisdiction and 907 current hierarchy should be masqueraded using this. 908 909local_no_masquerade 910 This feature prevents the local mailer from masquerading even 911 if MASQUERADE_AS is used. MASQUERADE_AS will only have effect 912 on addresses of mail going outside the local domain. 913 914masquerade_envelope 915 If masquerading is enabled (using MASQUERADE_AS) or the 916 genericstable is in use, this feature will cause envelope 917 addresses to also masquerade as being from the masquerade 918 host. Normally only the header addresses are masqueraded. 919 920genericstable This feature will cause unqualified addresses (i.e., without 921 a domain) and addresses with a domain listed in class {G} 922 to be looked up in a map and turned into another ("generic") 923 form, which can change both the domain name and the user name. 924 Notice: if you use an MSP (as it is default starting with 925 8.12), the MTA will only receive qualified addresses from the 926 MSP (as required by the RFCs). Hence you need to add your 927 domain to class {G}. This feature is similar to the userdb 928 functionality. The same types of addresses as for 929 masquerading are looked up, i.e., only header sender 930 addresses unless the allmasquerade and/or masquerade_envelope 931 features are given. Qualified addresses must have the domain 932 part in class {G}; entries can be added to this class by the 933 macros GENERICS_DOMAIN or GENERICS_DOMAIN_FILE (analogously 934 to MASQUERADE_DOMAIN and MASQUERADE_DOMAIN_FILE, see below). 935 936 The argument of FEATURE(`genericstable') may be the map 937 definition; the default map definition is: 938 939 hash /etc/mail/genericstable 940 941 The key for this table is either the full address, the domain 942 (with a leading @; the localpart is passed as first argument) 943 or the unqualified username (tried in the order mentioned); 944 the value is the new user address. If the new user address 945 does not include a domain, it will be qualified in the standard 946 manner, i.e., using $j or the masquerade name. Note that the 947 address being looked up must be fully qualified. For local 948 mail, it is necessary to use FEATURE(`always_add_domain') 949 for the addresses to be qualified. 950 The "+detail" of an address is passed as %1, so entries like 951 952 old+*@foo.org new+%1@example.com 953 gen+*@foo.org %1@example.com 954 955 and other forms are possible. 956 957generics_entire_domain 958 If the genericstable is enabled and GENERICS_DOMAIN or 959 GENERICS_DOMAIN_FILE is used, this feature will cause 960 addresses to be searched in the map if their domain 961 parts are subdomains of elements in class {G}. 962 963virtusertable A domain-specific form of aliasing, allowing multiple 964 virtual domains to be hosted on one machine. For example, 965 if the virtuser table contains: 966 967 info@foo.com foo-info 968 info@bar.com bar-info 969 joe@bar.com error:nouser 550 No such user here 970 jax@bar.com error:5.7.0:550 Address invalid 971 @baz.org jane@example.net 972 973 then mail addressed to info@foo.com will be sent to the 974 address foo-info, mail addressed to info@bar.com will be 975 delivered to bar-info, and mail addressed to anyone at baz.org 976 will be sent to jane@example.net, mail to joe@bar.com will 977 be rejected with the specified error message, and mail to 978 jax@bar.com will also have a RFC 1893 compliant error code 979 5.7.0. 980 981 The username from the original address is passed 982 as %1 allowing: 983 984 @foo.org %1@example.com 985 986 meaning someone@foo.org will be sent to someone@example.com. 987 Additionally, if the local part consists of "user+detail" 988 then "detail" is passed as %2 and "+detail" is passed as %3 989 when a match against user+* is attempted, so entries like 990 991 old+*@foo.org new+%2@example.com 992 gen+*@foo.org %2@example.com 993 +*@foo.org %1%3@example.com 994 X++@foo.org Z%3@example.com 995 @bar.org %1%3 996 997 and other forms are possible. Note: to preserve "+detail" 998 for a default case (@domain) %1%3 must be used as RHS. 999 There are two wildcards after "+": "+" matches only a non-empty 1000 detail, "*" matches also empty details, e.g., user+@foo.org 1001 matches +*@foo.org but not ++@foo.org. This can be used 1002 to ensure that the parameters %2 and %3 are not empty. 1003 1004 All the host names on the left hand side (foo.com, bar.com, 1005 and baz.org) must be in class {w} or class {VirtHost}. The 1006 latter can be defined by the macros VIRTUSER_DOMAIN or 1007 VIRTUSER_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and 1008 MASQUERADE_DOMAIN_FILE, see below). If VIRTUSER_DOMAIN or 1009 VIRTUSER_DOMAIN_FILE is used, then the entries of class 1010 {VirtHost} are added to class {R}, i.e., relaying is allowed 1011 to (and from) those domains, which by default includes also 1012 all subdomains (see relay_hosts_only). The default map 1013 definition is: 1014 1015 hash /etc/mail/virtusertable 1016 1017 A new definition can be specified as the second argument of 1018 the FEATURE macro, such as 1019 1020 FEATURE(`virtusertable', `dbm /etc/mail/virtusers') 1021 1022virtuser_entire_domain 1023 If the virtusertable is enabled and VIRTUSER_DOMAIN or 1024 VIRTUSER_DOMAIN_FILE is used, this feature will cause 1025 addresses to be searched in the map if their domain 1026 parts are subdomains of elements in class {VirtHost}. 1027 1028ldap_routing Implement LDAP-based e-mail recipient routing according to 1029 the Internet Draft draft-lachman-laser-ldap-mail-routing-01. 1030 This provides a method to re-route addresses with a 1031 domain portion in class {LDAPRoute} to either a 1032 different mail host or a different address. Hosts can 1033 be added to this class using LDAPROUTE_DOMAIN and 1034 LDAPROUTE_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and 1035 MASQUERADE_DOMAIN_FILE, see below). 1036 1037 See the LDAP ROUTING section below for more information. 1038 1039nullclient This is a special case -- it creates a configuration file 1040 containing nothing but support for forwarding all mail to a 1041 central hub via a local SMTP-based network. The argument 1042 is the name of that hub. 1043 1044 The only other feature that should be used in conjunction 1045 with this one is FEATURE(`nocanonify'). No mailers 1046 should be defined. No aliasing or forwarding is done. 1047 1048local_lmtp Use an LMTP capable local mailer. The argument to this 1049 feature is the pathname of an LMTP capable mailer. By 1050 default, mail.local is used. This is expected to be the 1051 mail.local which came with the 8.9 distribution which is 1052 LMTP capable. The path to mail.local is set by the 1053 confEBINDIR m4 variable -- making the default 1054 LOCAL_MAILER_PATH /usr/libexec/mail.local. 1055 If a different LMTP capable mailer is used, its pathname 1056 can be specified as second parameter and the arguments 1057 passed to it (A=) as third parameter, e.g., 1058 1059 FEATURE(`local_lmtp', `/usr/local/bin/lmtp', `lmtp') 1060 1061 WARNING: This feature sets LOCAL_MAILER_FLAGS unconditionally, 1062 i.e., without respecting any definitions in an OSTYPE setting. 1063 1064local_procmail Use procmail or another delivery agent as the local mailer. 1065 The argument to this feature is the pathname of the 1066 delivery agent, which defaults to PROCMAIL_MAILER_PATH. 1067 Note that this does NOT use PROCMAIL_MAILER_FLAGS or 1068 PROCMAIL_MAILER_ARGS for the local mailer; tweak 1069 LOCAL_MAILER_FLAGS and LOCAL_MAILER_ARGS instead, or 1070 specify the appropriate parameters. When procmail is used, 1071 the local mailer can make use of the 1072 "user+indicator@local.host" syntax; normally the +indicator 1073 is just tossed, but by default it is passed as the -a 1074 argument to procmail. 1075 1076 This feature can take up to three arguments: 1077 1078 1. Path to the mailer program 1079 [default: /usr/local/bin/procmail] 1080 2. Argument vector including name of the program 1081 [default: procmail -Y -a $h -d $u] 1082 3. Flags for the mailer [default: SPfhn9] 1083 1084 Empty arguments cause the defaults to be taken. 1085 Note that if you are on a system with a broken 1086 setreuid() call, you may need to add -f $f to the procmail 1087 argument vector to pass the proper sender to procmail. 1088 1089 For example, this allows it to use the maildrop 1090 (http://www.flounder.net/~mrsam/maildrop/) mailer instead 1091 by specifying: 1092 1093 FEATURE(`local_procmail', `/usr/local/bin/maildrop', 1094 `maildrop -d $u') 1095 1096 or scanmails using: 1097 1098 FEATURE(`local_procmail', `/usr/local/bin/scanmails') 1099 1100 WARNING: This feature sets LOCAL_MAILER_FLAGS unconditionally, 1101 i.e., without respecting any definitions in an OSTYPE setting. 1102 1103bestmx_is_local Accept mail as though locally addressed for any host that 1104 lists us as the best possible MX record. This generates 1105 additional DNS traffic, but should be OK for low to 1106 medium traffic hosts. The argument may be a set of 1107 domains, which will limit the feature to only apply to 1108 these domains -- this will reduce unnecessary DNS 1109 traffic. THIS FEATURE IS FUNDAMENTALLY INCOMPATIBLE WITH 1110 WILDCARD MX RECORDS!!! If you have a wildcard MX record 1111 that matches your domain, you cannot use this feature. 1112 1113smrsh Use the SendMail Restricted SHell (smrsh) provided 1114 with the distribution instead of /bin/sh for mailing 1115 to programs. This improves the ability of the local 1116 system administrator to control what gets run via 1117 e-mail. If an argument is provided it is used as the 1118 pathname to smrsh; otherwise, the path defined by 1119 confEBINDIR is used for the smrsh binary -- by default, 1120 /usr/libexec/smrsh is assumed. 1121 1122promiscuous_relay 1123 By default, the sendmail configuration files do not permit 1124 mail relaying (that is, accepting mail from outside your 1125 local host (class {w}) and sending it to another host than 1126 your local host). This option sets your site to allow 1127 mail relaying from any site to any site. In almost all 1128 cases, it is better to control relaying more carefully 1129 with the access map, class {R}, or authentication. Domains 1130 can be added to class {R} by the macros RELAY_DOMAIN or 1131 RELAY_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and 1132 MASQUERADE_DOMAIN_FILE, see below). 1133 1134relay_entire_domain 1135 This option allows any host in your domain as defined by 1136 class {m} to use your server for relaying. Notice: make 1137 sure that your domain is not just a top level domain, 1138 e.g., com. This can happen if you give your host a name 1139 like example.com instead of host.example.com. 1140 1141relay_hosts_only 1142 By default, names that are listed as RELAY in the access 1143 db and class {R} are treated as domain names, not host names. 1144 For example, if you specify ``foo.com'', then mail to or 1145 from foo.com, abc.foo.com, or a.very.deep.domain.foo.com 1146 will all be accepted for relaying. This feature changes 1147 the behaviour to look up individual host names only. 1148 1149relay_based_on_MX 1150 Turns on the ability to allow relaying based on the MX 1151 records of the host portion of an incoming recipient; that 1152 is, if an MX record for host foo.com points to your site, 1153 you will accept and relay mail addressed to foo.com. See 1154 description below for more information before using this 1155 feature. Also, see the KNOWNBUGS entry regarding bestmx 1156 map lookups. 1157 1158 FEATURE(`relay_based_on_MX') does not necessarily allow 1159 routing of these messages which you expect to be allowed, 1160 if route address syntax (or %-hack syntax) is used. If 1161 this is a problem, add entries to the access-table or use 1162 FEATURE(`loose_relay_check'). 1163 1164relay_mail_from 1165 Allows relaying if the mail sender is listed as RELAY in 1166 the access map. If an optional argument `domain' (this 1167 is the literal word `domain', not a placeholder) is given, 1168 relaying can be allowed just based on the domain portion 1169 of the sender address. This feature should only be used if 1170 absolutely necessary as the sender address can be easily 1171 forged. Use of this feature requires the "From:" tag to 1172 be used for the key in the access map; see the discussion 1173 of tags and FEATURE(`relay_mail_from') in the section on 1174 anti-spam configuration control. 1175 1176relay_local_from 1177 Allows relaying if the domain portion of the mail sender 1178 is a local host. This should only be used if absolutely 1179 necessary as it opens a window for spammers. Specifically, 1180 they can send mail to your mail server that claims to be 1181 from your domain (either directly or via a routed address), 1182 and you will go ahead and relay it out to arbitrary hosts 1183 on the Internet. 1184 1185accept_unqualified_senders 1186 Normally, MAIL FROM: commands in the SMTP session will be 1187 refused if the connection is a network connection and the 1188 sender address does not include a domain name. If your 1189 setup sends local mail unqualified (i.e., MAIL FROM:<joe>), 1190 you will need to use this feature to accept unqualified 1191 sender addresses. Setting the DaemonPortOptions modifier 1192 'u' overrides the default behavior, i.e., unqualified 1193 addresses are accepted even without this FEATURE. 1194 If this FEATURE is not used, the DaemonPortOptions modifier 1195 'f' can be used to enforce fully qualified addresses. 1196 1197accept_unresolvable_domains 1198 Normally, MAIL FROM: commands in the SMTP session will be 1199 refused if the host part of the argument to MAIL FROM: 1200 cannot be located in the host name service (e.g., an A or 1201 MX record in DNS). If you are inside a firewall that has 1202 only a limited view of the Internet host name space, this 1203 could cause problems. In this case you probably want to 1204 use this feature to accept all domains on input, even if 1205 they are unresolvable. 1206 1207access_db Turns on the access database feature. The access db gives 1208 you the ability to allow or refuse to accept mail from 1209 specified domains for administrative reasons. Moreover, 1210 it can control the behavior of sendmail in various situations. 1211 By default, the access database specification is: 1212 1213 hash -T<TMPF> /etc/mail/access 1214 1215 See the anti-spam configuration control section for further 1216 important information about this feature. Notice: 1217 "-T<TMPF>" is meant literal, do not replace it by anything. 1218 1219blacklist_recipients 1220 Turns on the ability to block incoming mail for certain 1221 recipient usernames, hostnames, or addresses. For 1222 example, you can block incoming mail to user nobody, 1223 host foo.mydomain.com, or guest@bar.mydomain.com. 1224 These specifications are put in the access db as 1225 described in the anti-spam configuration control section 1226 later in this document. 1227 1228delay_checks The rulesets check_mail and check_relay will not be called 1229 when a client connects or issues a MAIL command, respectively. 1230 Instead, those rulesets will be called by the check_rcpt 1231 ruleset; they will be skipped under certain circumstances. 1232 See "Delay all checks" in the anti-spam configuration control 1233 section. Note: this feature is incompatible to the versions 1234 in 8.10 and 8.11. 1235 1236use_client_ptr If this feature is enabled then check_relay will override 1237 its first argument with $&{client_ptr}. This is useful for 1238 rejections based on the unverified hostname of client, 1239 which turns on the same behavior as in earlier sendmail 1240 versions when delay_checks was not in use. See doc/op/op.* 1241 about check_relay, {client_name}, and {client_ptr}. 1242 1243dnsbl Turns on rejection, discarding, or quarantining of hosts 1244 found in a DNS based list. The first argument is used as 1245 the domain in which blocked hosts are listed. A second 1246 argument can be used to change the default error message, 1247 or select one of the operations `discard' and `quarantine'. 1248 Without that second argument, the error message will be 1249 1250 Rejected: IP-ADDRESS listed at SERVER 1251 1252 where IP-ADDRESS and SERVER are replaced by the appropriate 1253 information. By default, temporary lookup failures are 1254 ignored. This behavior can be changed by specifying a 1255 third argument, which must be either `t' or a full error 1256 message. See the anti-spam configuration control section for 1257 an example. The dnsbl feature can be included several times 1258 to query different DNS based rejection lists. See also 1259 enhdnsbl for an enhanced version. 1260 1261 Set the DNSBL_MAP mc option to change the default map 1262 definition from `host'. Set the DNSBL_MAP_OPT mc option 1263 to add additional options to the map specification used. 1264 1265 Some DNS based rejection lists cause failures if asked 1266 for AAAA records. If your sendmail version is compiled 1267 with IPv6 support (NETINET6) and you experience this 1268 problem, add 1269 1270 define(`DNSBL_MAP', `dns -R A') 1271 1272 before the first use of this feature. Alternatively you 1273 can use enhdnsbl instead (see below). Moreover, this 1274 statement can be used to reduce the number of DNS retries, 1275 e.g., 1276 1277 define(`DNSBL_MAP', `dns -R A -r2') 1278 1279 See below (EDNSBL_TO) for an explanation. 1280 1281enhdnsbl Enhanced version of dnsbl (see above). Further arguments 1282 (up to 5) can be used to specify specific return values 1283 from lookups. Temporary lookup failures are ignored unless 1284 a third argument is given, which must be either `t' or a full 1285 error message. By default, any successful lookup will 1286 generate an error. Otherwise the result of the lookup is 1287 compared with the supplied argument(s), and only if a match 1288 occurs an error is generated. For example, 1289 1290 FEATURE(`enhdnsbl', `dnsbl.example.com', `', `t', `127.0.0.2.') 1291 1292 will reject the e-mail if the lookup returns the value 1293 ``127.0.0.2.'', or generate a 451 response if the lookup 1294 temporarily failed. The arguments can contain metasymbols 1295 as they are allowed in the LHS of rules. As the example 1296 shows, the default values are also used if an empty argument, 1297 i.e., `', is specified. This feature requires that sendmail 1298 has been compiled with the flag DNSMAP (see sendmail/README). 1299 1300 Set the EDNSBL_TO mc option to change the DNS retry count 1301 from the default value of 5, this can be very useful when 1302 a DNS server is not responding, which in turn may cause 1303 clients to time out (an entry stating 1304 1305 did not issue MAIL/EXPN/VRFY/ETRN 1306 1307 will be logged). 1308 1309ratecontrol Enable simple ruleset to do connection rate control 1310 checking. This requires entries in access_db of the form 1311 1312 ClientRate:IP.ADD.RE.SS LIMIT 1313 1314 The RHS specifies the maximum number of connections 1315 (an integer number) over the time interval defined 1316 by ConnectionRateWindowSize, where 0 means unlimited. 1317 1318 Take the following example: 1319 1320 ClientRate:10.1.2.3 4 1321 ClientRate:127.0.0.1 0 1322 ClientRate: 10 1323 1324 10.1.2.3 can only make up to 4 connections, the 1325 general limit it 10, and 127.0.0.1 can make an unlimited 1326 number of connections per ConnectionRateWindowSize. 1327 1328 See also CONNECTION CONTROL. 1329 1330conncontrol Enable a simple check of the number of incoming SMTP 1331 connections. This requires entries in access_db of the 1332 form 1333 1334 ClientConn:IP.ADD.RE.SS LIMIT 1335 1336 The RHS specifies the maximum number of open connections 1337 (an integer number). 1338 1339 Take the following example: 1340 1341 ClientConn:10.1.2.3 4 1342 ClientConn:127.0.0.1 0 1343 ClientConn: 10 1344 1345 10.1.2.3 can only have up to 4 open connections, the 1346 general limit it 10, and 127.0.0.1 does not have any 1347 explicit limit. 1348 1349 See also CONNECTION CONTROL. 1350 1351mtamark Experimental support for "Marking Mail Transfer Agents in 1352 Reverse DNS with TXT RRs" (MTAMark), see 1353 draft-stumpf-dns-mtamark-01. Optional arguments are: 1354 1355 1. Error message, default: 1356 1357 550 Rejected: $&{client_addr} not listed as MTA 1358 1359 2. Temporary lookup failures are ignored unless a second 1360 argument is given, which must be either `t' or a full 1361 error message. 1362 1363 3. Lookup prefix, default: _perm._smtp._srv. This should 1364 not be changed unless the draft changes it. 1365 1366 Example: 1367 1368 FEATURE(`mtamark', `', `t') 1369 1370lookupdotdomain Look up also .domain in the access map. This allows to 1371 match only subdomains. It does not work well with 1372 FEATURE(`relay_hosts_only'), because most lookups for 1373 subdomains are suppressed by the latter feature. 1374 1375loose_relay_check 1376 Normally, if % addressing is used for a recipient, e.g. 1377 user%site@othersite, and othersite is in class {R}, the 1378 check_rcpt ruleset will strip @othersite and recheck 1379 user@site for relaying. This feature changes that 1380 behavior. It should not be needed for most installations. 1381 1382authinfo Provide a separate map for client side authentication 1383 information. See SMTP AUTHENTICATION for details. 1384 By default, the authinfo database specification is: 1385 1386 hash /etc/mail/authinfo 1387 1388preserve_luser_host 1389 Preserve the name of the recipient host if LUSER_RELAY is 1390 used. Without this option, the domain part of the 1391 recipient address will be replaced by the host specified as 1392 LUSER_RELAY. This feature only works if the hostname is 1393 passed to the mailer (see mailer triple in op.me). Note 1394 that in the default configuration the local mailer does not 1395 receive the hostname, i.e., the mailer triple has an empty 1396 hostname. 1397 1398preserve_local_plus_detail 1399 Preserve the +detail portion of the address when passing 1400 address to local delivery agent. Disables alias and 1401 .forward +detail stripping (e.g., given user+detail, only 1402 that address will be looked up in the alias file; user+* and 1403 user will not be looked up). Only use if the local 1404 delivery agent in use supports +detail addressing. 1405 Moreover, this will most likely not work if the 'w' flag 1406 for the local mailer is set as the entire local address 1407 including +detail is passed to the user lookup function. 1408 1409compat_check Enable ruleset check_compat to look up pairs of addresses 1410 with the Compat: tag -- Compat:sender<@>recipient -- in the 1411 access map. Valid values for the RHS include 1412 DISCARD silently discard recipient 1413 TEMP: return a temporary error 1414 ERROR: return a permanent error 1415 In the last two cases, a 4xy/5xy SMTP reply code should 1416 follow the colon. 1417 1418no_default_msa Don't generate the default MSA daemon, i.e., 1419 DAEMON_OPTIONS(`Port=587,Name=MSA,M=E') 1420 To define a MSA daemon with other parameters, use this 1421 FEATURE and introduce new settings via DAEMON_OPTIONS(). 1422 1423msp Defines config file for Message Submission Program. 1424 See sendmail/SECURITY for details and cf/cf/submit.mc how 1425 to use it. An optional argument can be used to override 1426 the default of `[localhost]' to use as host to send all 1427 e-mails to. Note that MX records will be used if the 1428 specified hostname is not in square brackets (e.g., 1429 [hostname]). If `MSA' is specified as second argument then 1430 port 587 is used to contact the server. Example: 1431 1432 FEATURE(`msp', `', `MSA') 1433 1434 Some more hints about possible changes can be found below 1435 in the section MESSAGE SUBMISSION PROGRAM. 1436 1437 Note: Due to many problems, submit.mc uses 1438 1439 FEATURE(`msp', `[127.0.0.1]') 1440 1441 by default. If you have a machine with IPv6 only, 1442 change it to 1443 1444 FEATURE(`msp', `[IPv6:::1]') 1445 1446 If you want to continue using '[localhost]', (the behavior 1447 up to 8.12.6), use 1448 1449 FEATURE(`msp') 1450 1451queuegroup A simple example how to select a queue group based 1452 on the full e-mail address or the domain of the 1453 recipient. Selection is done via entries in the 1454 access map using the tag QGRP:, for example: 1455 1456 QGRP:example.com main 1457 QGRP:friend@some.org others 1458 QGRP:my.domain local 1459 1460 where "main", "others", and "local" are names of 1461 queue groups. If an argument is specified, it is used 1462 as default queue group. 1463 1464 Note: please read the warning in doc/op/op.me about 1465 queue groups and possible queue manipulations. 1466 1467greet_pause Adds the greet_pause ruleset which enables open proxy 1468 and SMTP slamming protection. The feature can take an 1469 argument specifying the milliseconds to wait: 1470 1471 FEATURE(`greet_pause', `5000') dnl 5 seconds 1472 1473 If FEATURE(`access_db') is enabled, an access database 1474 lookup with the GreetPause tag is done using client 1475 hostname, domain, IP address, or subnet to determine the 1476 pause time: 1477 1478 GreetPause:my.domain 0 1479 GreetPause:example.com 5000 1480 GreetPause:10.1.2 2000 1481 GreetPause:127.0.0.1 0 1482 1483 When using FEATURE(`access_db'), the optional 1484 FEATURE(`greet_pause') argument becomes the default if 1485 nothing is found in the access database. A ruleset called 1486 Local_greet_pause can be used for local modifications, e.g., 1487 1488 LOCAL_RULESETS 1489 SLocal_greet_pause 1490 R$* $: $&{daemon_flags} 1491 R$* a $* $# 0 1492 1493block_bad_helo Reject messages from SMTP clients which provide a HELO/EHLO 1494 argument which is either unqualified, or is one of our own 1495 names (i.e., the server name instead of the client name). 1496 This check is performed at RCPT stage and disabled for the 1497 following cases: 1498 - authenticated sessions, 1499 - connections from IP addresses in class $={R}. 1500 Currently access_db lookups can not be used to 1501 (selectively) disable this test, moreover, 1502 FEATURE(`delay_checks') 1503 is required. 1504 1505require_rdns Reject mail from connecting SMTP clients without proper 1506 rDNS (reverse DNS), functional gethostbyaddr() resolution. 1507 Note: this feature will cause false positives, i.e., there 1508 are legitimate MTAs that do not have proper DNS entries. 1509 Rejecting mails from those MTAs is a local policy decision. 1510 1511 The basic policy is to reject message with a 5xx error if 1512 the IP address fails to resolve. However, if this is a 1513 temporary failure, a 4xx temporary failure is returned. 1514 If the look-up succeeds, but returns an apparently forged 1515 value, this is treated as a temporary failure with a 4xx 1516 error code. 1517 1518 EXCEPTIONS: 1519 1520 Exceptions based on access entries are discussed below. 1521 Any IP address matched using $=R (the "relay-domains" file) 1522 is excepted from the rules. Since we have explicitly 1523 allowed relaying for this host, based on IP address, we 1524 ignore the rDNS failure. 1525 1526 The philosophical assumption here is that most users do 1527 not control their rDNS. They should be able to send mail 1528 through their ISP, whether or not they have valid rDNS. 1529 The class $=R, roughly speaking, contains those IP addresses 1530 and address ranges for which we are the ISP, or are acting 1531 as if the ISP. 1532 1533 If `delay_checks' is in effect (recommended), then any 1534 sender who has authenticated is also excepted from the 1535 restrictions. This happens because the rules produced by 1536 this FEATURE() will not be applied to authenticated senders 1537 (assuming `delay_checks'). 1538 1539 ACCESS MAP ENTRIES: 1540 1541 Entries such as 1542 Connect:1.2.3.4 OK 1543 Connect:1.2 RELAY 1544 will whitelist IP address 1.2.3.4, so that the rDNS 1545 blocking does apply to that IP address 1546 1547 Entries such as 1548 Connect:1.2.3.4 REJECT 1549 will have the effect of forcing a temporary failure for 1550 that address to be treated as a permanent failure. 1551 1552badmx Reject envelope sender addresses (MAIL) whose domain part 1553 resolves to a "bad" MX record. By default these are 1554 MX records which resolve to A records that match the 1555 regular expression: 1556 1557 ^(127\.|10\.|0\.0\.0\.0) 1558 1559 This default regular expression can be overridden by 1560 specifying an argument, e.g., 1561 1562 FEATURE(`badmx', `^127\.0\.0\.1') 1563 1564 Note: this feature requires that the sendmail binary 1565 has been compiled with the options MAP_REGEX and 1566 DNSMAP. 1567 1568+-------+ 1569| HACKS | 1570+-------+ 1571 1572Some things just can't be called features. To make this clear, 1573they go in the hack subdirectory and are referenced using the HACK 1574macro. These will tend to be site-dependent. The release 1575includes the Berkeley-dependent "cssubdomain" hack (that makes 1576sendmail accept local names in either Berkeley.EDU or CS.Berkeley.EDU; 1577this is intended as a short-term aid while moving hosts into 1578subdomains. 1579 1580 1581+--------------------+ 1582| SITE CONFIGURATION | 1583+--------------------+ 1584 1585 ***************************************************** 1586 * This section is really obsolete, and is preserved * 1587 * only for back compatibility. You should plan on * 1588 * using mailertables for new installations. In * 1589 * particular, it doesn't work for the newer forms * 1590 * of UUCP mailers, such as uucp-uudom. * 1591 ***************************************************** 1592 1593Complex sites will need more local configuration information, such as 1594lists of UUCP hosts they speak with directly. This can get a bit more 1595tricky. For an example of a "complex" site, see cf/ucbvax.mc. 1596 1597The SITECONFIG macro allows you to indirectly reference site-dependent 1598configuration information stored in the siteconfig subdirectory. For 1599example, the line 1600 1601 SITECONFIG(`uucp.ucbvax', `ucbvax', `U') 1602 1603reads the file uucp.ucbvax for local connection information. The 1604second parameter is the local name (in this case just "ucbvax" since 1605it is locally connected, and hence a UUCP hostname). The third 1606parameter is the name of both a macro to store the local name (in 1607this case, {U}) and the name of the class (e.g., {U}) in which to store 1608the host information read from the file. Another SITECONFIG line reads 1609 1610 SITECONFIG(`uucp.ucbarpa', `ucbarpa.Berkeley.EDU', `W') 1611 1612This says that the file uucp.ucbarpa contains the list of UUCP sites 1613connected to ucbarpa.Berkeley.EDU. Class {W} will be used to 1614store this list, and $W is defined to be ucbarpa.Berkeley.EDU, that 1615is, the name of the relay to which the hosts listed in uucp.ucbarpa 1616are connected. [The machine ucbarpa is gone now, but this 1617out-of-date configuration file has been left around to demonstrate 1618how you might do this.] 1619 1620Note that the case of SITECONFIG with a third parameter of ``U'' is 1621special; the second parameter is assumed to be the UUCP name of the 1622local site, rather than the name of a remote site, and the UUCP name 1623is entered into class {w} (the list of local hostnames) as $U.UUCP. 1624 1625The siteconfig file (e.g., siteconfig/uucp.ucbvax.m4) contains nothing 1626more than a sequence of SITE macros describing connectivity. For 1627example: 1628 1629 SITE(`cnmat') 1630 SITE(`sgi olympus') 1631 1632The second example demonstrates that you can use two names on the 1633same line; these are usually aliases for the same host (or are at 1634least in the same company). 1635 1636The macro LOCAL_UUCP can be used to add rules into the generated 1637cf file at the place where MAILER(`uucp') inserts its rules. This 1638should only be used if really necessary. 1639 1640+--------------------+ 1641| USING UUCP MAILERS | 1642+--------------------+ 1643 1644It's hard to get UUCP mailers right because of the extremely ad hoc 1645nature of UUCP addressing. These config files are really designed 1646for domain-based addressing, even for UUCP sites. 1647 1648There are four UUCP mailers available. The choice of which one to 1649use is partly a matter of local preferences and what is running at 1650the other end of your UUCP connection. Unlike good protocols that 1651define what will go over the wire, UUCP uses the policy that you 1652should do what is right for the other end; if they change, you have 1653to change. This makes it hard to do the right thing, and discourages 1654people from updating their software. In general, if you can avoid 1655UUCP, please do. 1656 1657The major choice is whether to go for a domainized scheme or a 1658non-domainized scheme. This depends entirely on what the other 1659end will recognize. If at all possible, you should encourage the 1660other end to go to a domain-based system -- non-domainized addresses 1661don't work entirely properly. 1662 1663The four mailers are: 1664 1665 uucp-old (obsolete name: "uucp") 1666 This is the oldest, the worst (but the closest to UUCP) way of 1667 sending messages across UUCP connections. It does bangify 1668 everything and prepends $U (your UUCP name) to the sender's 1669 address (which can already be a bang path itself). It can 1670 only send to one address at a time, so it spends a lot of 1671 time copying duplicates of messages. Avoid this if at all 1672 possible. 1673 1674 uucp-new (obsolete name: "suucp") 1675 The same as above, except that it assumes that in one rmail 1676 command you can specify several recipients. It still has a 1677 lot of other problems. 1678 1679 uucp-dom 1680 This UUCP mailer keeps everything as domain addresses. 1681 Basically, it uses the SMTP mailer rewriting rules. This mailer 1682 is only included if MAILER(`smtp') is specified before 1683 MAILER(`uucp'). 1684 1685 Unfortunately, a lot of UUCP mailer transport agents require 1686 bangified addresses in the envelope, although you can use 1687 domain-based addresses in the message header. (The envelope 1688 shows up as the From_ line on UNIX mail.) So.... 1689 1690 uucp-uudom 1691 This is a cross between uucp-new (for the envelope addresses) 1692 and uucp-dom (for the header addresses). It bangifies the 1693 envelope sender (From_ line in messages) without adding the 1694 local hostname, unless there is no host name on the address 1695 at all (e.g., "wolf") or the host component is a UUCP host name 1696 instead of a domain name ("somehost!wolf" instead of 1697 "some.dom.ain!wolf"). This is also included only if MAILER(`smtp') 1698 is also specified earlier. 1699 1700Examples: 1701 1702On host grasp.insa-lyon.fr (UUCP host name "grasp"), the following 1703summarizes the sender rewriting for various mailers. 1704 1705Mailer sender rewriting in the envelope 1706------ ------ ------------------------- 1707uucp-{old,new} wolf grasp!wolf 1708uucp-dom wolf wolf@grasp.insa-lyon.fr 1709uucp-uudom wolf grasp.insa-lyon.fr!wolf 1710 1711uucp-{old,new} wolf@fr.net grasp!fr.net!wolf 1712uucp-dom wolf@fr.net wolf@fr.net 1713uucp-uudom wolf@fr.net fr.net!wolf 1714 1715uucp-{old,new} somehost!wolf grasp!somehost!wolf 1716uucp-dom somehost!wolf somehost!wolf@grasp.insa-lyon.fr 1717uucp-uudom somehost!wolf grasp.insa-lyon.fr!somehost!wolf 1718 1719If you are using one of the domainized UUCP mailers, you really want 1720to convert all UUCP addresses to domain format -- otherwise, it will 1721do it for you (and probably not the way you expected). For example, 1722if you have the address foo!bar!baz (and you are not sending to foo), 1723the heuristics will add the @uucp.relay.name or @local.host.name to 1724this address. However, if you map foo to foo.host.name first, it 1725will not add the local hostname. You can do this using the uucpdomain 1726feature. 1727 1728 1729+-------------------+ 1730| TWEAKING RULESETS | 1731+-------------------+ 1732 1733For more complex configurations, you can define special rules. 1734The macro LOCAL_RULE_3 introduces rules that are used in canonicalizing 1735the names. Any modifications made here are reflected in the header. 1736 1737A common use is to convert old UUCP addresses to SMTP addresses using 1738the UUCPSMTP macro. For example: 1739 1740 LOCAL_RULE_3 1741 UUCPSMTP(`decvax', `decvax.dec.com') 1742 UUCPSMTP(`research', `research.att.com') 1743 1744will cause addresses of the form "decvax!user" and "research!user" 1745to be converted to "user@decvax.dec.com" and "user@research.att.com" 1746respectively. 1747 1748This could also be used to look up hosts in a database map: 1749 1750 LOCAL_RULE_3 1751 R$* < @ $+ > $* $: $1 < @ $(hostmap $2 $) > $3 1752 1753This map would be defined in the LOCAL_CONFIG portion, as shown below. 1754 1755Similarly, LOCAL_RULE_0 can be used to introduce new parsing rules. 1756For example, new rules are needed to parse hostnames that you accept 1757via MX records. For example, you might have: 1758 1759 LOCAL_RULE_0 1760 R$+ <@ host.dom.ain.> $#uucp $@ cnmat $: $1 < @ host.dom.ain.> 1761 1762You would use this if you had installed an MX record for cnmat.Berkeley.EDU 1763pointing at this host; this rule catches the message and forwards it on 1764using UUCP. 1765 1766You can also tweak rulesets 1 and 2 using LOCAL_RULE_1 and LOCAL_RULE_2. 1767These rulesets are normally empty. 1768 1769A similar macro is LOCAL_CONFIG. This introduces lines added after the 1770boilerplate option setting but before rulesets. Do not declare rulesets in 1771the LOCAL_CONFIG section. It can be used to declare local database maps or 1772whatever. For example: 1773 1774 LOCAL_CONFIG 1775 Khostmap hash /etc/mail/hostmap 1776 Kyplocal nis -m hosts.byname 1777 1778 1779+---------------------------+ 1780| MASQUERADING AND RELAYING | 1781+---------------------------+ 1782 1783You can have your host masquerade as another using 1784 1785 MASQUERADE_AS(`host.domain') 1786 1787This causes mail being sent to be labeled as coming from the 1788indicated host.domain, rather than $j. One normally masquerades as 1789one of one's own subdomains (for example, it's unlikely that 1790Berkeley would choose to masquerade as an MIT site). This 1791behaviour is modified by a plethora of FEATUREs; in particular, see 1792masquerade_envelope, allmasquerade, limited_masquerade, and 1793masquerade_entire_domain. 1794 1795The masquerade name is not normally canonified, so it is important 1796that it be your One True Name, that is, fully qualified and not a 1797CNAME. However, if you use a CNAME, the receiving side may canonify 1798it for you, so don't think you can cheat CNAME mapping this way. 1799 1800Normally the only addresses that are masqueraded are those that come 1801from this host (that is, are either unqualified or in class {w}, the list 1802of local domain names). You can augment this list, which is realized 1803by class {M} using 1804 1805 MASQUERADE_DOMAIN(`otherhost.domain') 1806 1807The effect of this is that although mail to user@otherhost.domain 1808will not be delivered locally, any mail including any user@otherhost.domain 1809will, when relayed, be rewritten to have the MASQUERADE_AS address. 1810This can be a space-separated list of names. 1811 1812If these names are in a file, you can use 1813 1814 MASQUERADE_DOMAIN_FILE(`filename') 1815 1816to read the list of names from the indicated file (i.e., to add 1817elements to class {M}). 1818 1819To exempt hosts or subdomains from being masqueraded, you can use 1820 1821 MASQUERADE_EXCEPTION(`host.domain') 1822 1823This can come handy if you want to masquerade a whole domain 1824except for one (or a few) host(s). If these names are in a file, 1825you can use 1826 1827 MASQUERADE_EXCEPTION_FILE(`filename') 1828 1829Normally only header addresses are masqueraded. If you want to 1830masquerade the envelope as well, use 1831 1832 FEATURE(`masquerade_envelope') 1833 1834There are always users that need to be "exposed" -- that is, their 1835internal site name should be displayed instead of the masquerade name. 1836Root is an example (which has been "exposed" by default prior to 8.10). 1837You can add users to this list using 1838 1839 EXPOSED_USER(`usernames') 1840 1841This adds users to class {E}; you could also use 1842 1843 EXPOSED_USER_FILE(`filename') 1844 1845You can also arrange to relay all unqualified names (that is, names 1846without @host) to a relay host. For example, if you have a central 1847email server, you might relay to that host so that users don't have 1848to have .forward files or aliases. You can do this using 1849 1850 define(`LOCAL_RELAY', `mailer:hostname') 1851 1852The ``mailer:'' can be omitted, in which case the mailer defaults to 1853"relay". There are some user names that you don't want relayed, perhaps 1854because of local aliases. A common example is root, which may be 1855locally aliased. You can add entries to this list using 1856 1857 LOCAL_USER(`usernames') 1858 1859This adds users to class {L}; you could also use 1860 1861 LOCAL_USER_FILE(`filename') 1862 1863If you want all incoming mail sent to a centralized hub, as for a 1864shared /var/spool/mail scheme, use 1865 1866 define(`MAIL_HUB', `mailer:hostname') 1867 1868Again, ``mailer:'' defaults to "relay". If you define both LOCAL_RELAY 1869and MAIL_HUB _AND_ you have FEATURE(`stickyhost'), unqualified names will 1870be sent to the LOCAL_RELAY and other local names will be sent to MAIL_HUB. 1871Note: there is a (long standing) bug which keeps this combination from 1872working for addresses of the form user+detail. 1873Names in class {L} will be delivered locally, so you MUST have aliases or 1874.forward files for them. 1875 1876For example, if you are on machine mastodon.CS.Berkeley.EDU and you have 1877FEATURE(`stickyhost'), the following combinations of settings will have the 1878indicated effects: 1879 1880email sent to.... eric eric@mastodon.CS.Berkeley.EDU 1881 1882LOCAL_RELAY set to mail.CS.Berkeley.EDU (delivered locally) 1883mail.CS.Berkeley.EDU (no local aliasing) (aliasing done) 1884 1885MAIL_HUB set to mammoth.CS.Berkeley.EDU mammoth.CS.Berkeley.EDU 1886mammoth.CS.Berkeley.EDU (aliasing done) (aliasing done) 1887 1888Both LOCAL_RELAY and mail.CS.Berkeley.EDU mammoth.CS.Berkeley.EDU 1889MAIL_HUB set as above (no local aliasing) (aliasing done) 1890 1891If you do not have FEATURE(`stickyhost') set, then LOCAL_RELAY and 1892MAIL_HUB act identically, with MAIL_HUB taking precedence. 1893 1894If you want all outgoing mail to go to a central relay site, define 1895SMART_HOST as well. Briefly: 1896 1897 LOCAL_RELAY applies to unqualified names (e.g., "eric"). 1898 MAIL_HUB applies to names qualified with the name of the 1899 local host (e.g., "eric@mastodon.CS.Berkeley.EDU"). 1900 SMART_HOST applies to names qualified with other hosts or 1901 bracketed addresses (e.g., "eric@mastodon.CS.Berkeley.EDU" 1902 or "eric@[127.0.0.1]"). 1903 1904However, beware that other relays (e.g., UUCP_RELAY, BITNET_RELAY, 1905DECNET_RELAY, and FAX_RELAY) take precedence over SMART_HOST, so if you 1906really want absolutely everything to go to a single central site you will 1907need to unset all the other relays -- or better yet, find or build a 1908minimal config file that does this. 1909 1910For duplicate suppression to work properly, the host name is best 1911specified with a terminal dot: 1912 1913 define(`MAIL_HUB', `host.domain.') 1914 note the trailing dot ---^ 1915 1916 1917+-------------------------------------------+ 1918| USING LDAP FOR ALIASES, MAPS, AND CLASSES | 1919+-------------------------------------------+ 1920 1921LDAP can be used for aliases, maps, and classes by either specifying your 1922own LDAP map specification or using the built-in default LDAP map 1923specification. The built-in default specifications all provide lookups 1924which match against either the machine's fully qualified hostname (${j}) or 1925a "cluster". The cluster allows you to share LDAP entries among a large 1926number of machines without having to enter each of the machine names into 1927each LDAP entry. To set the LDAP cluster name to use for a particular 1928machine or set of machines, set the confLDAP_CLUSTER m4 variable to a 1929unique name. For example: 1930 1931 define(`confLDAP_CLUSTER', `Servers') 1932 1933Here, the word `Servers' will be the cluster name. As an example, assume 1934that smtp.sendmail.org, etrn.sendmail.org, and mx.sendmail.org all belong 1935to the Servers cluster. 1936 1937Some of the LDAP LDIF examples below show use of the Servers cluster. 1938Every entry must have either a sendmailMTAHost or sendmailMTACluster 1939attribute or it will be ignored. Be careful as mixing clusters and 1940individual host records can have surprising results (see the CAUTION 1941sections below). 1942 1943See the file cf/sendmail.schema for the actual LDAP schemas. Note that 1944this schema (and therefore the lookups and examples below) is experimental 1945at this point as it has had little public review. Therefore, it may change 1946in future versions. Feedback via sendmail-YYYY@support.sendmail.org is 1947encouraged (replace YYYY with the current year, e.g., 2005). 1948 1949------- 1950Aliases 1951------- 1952 1953The ALIAS_FILE (O AliasFile) option can be set to use LDAP for alias 1954lookups. To use the default schema, simply use: 1955 1956 define(`ALIAS_FILE', `ldap:') 1957 1958By doing so, you will use the default schema which expands to a map 1959declared as follows: 1960 1961 ldap -k (&(objectClass=sendmailMTAAliasObject) 1962 (sendmailMTAAliasGrouping=aliases) 1963 (|(sendmailMTACluster=${sendmailMTACluster}) 1964 (sendmailMTAHost=$j)) 1965 (sendmailMTAKey=%0)) 1966 -v sendmailMTAAliasValue,sendmailMTAAliasSearch:FILTER:sendmailMTAAliasObject,sendmailMTAAliasURL:URL:sendmailMTAAliasObject 1967 1968 1969NOTE: The macros shown above ${sendmailMTACluster} and $j are not actually 1970used when the binary expands the `ldap:' token as the AliasFile option is 1971not actually macro-expanded when read from the sendmail.cf file. 1972 1973Example LDAP LDIF entries might be: 1974 1975 dn: sendmailMTAKey=sendmail-list, dc=sendmail, dc=org 1976 objectClass: sendmailMTA 1977 objectClass: sendmailMTAAlias 1978 objectClass: sendmailMTAAliasObject 1979 sendmailMTAAliasGrouping: aliases 1980 sendmailMTAHost: etrn.sendmail.org 1981 sendmailMTAKey: sendmail-list 1982 sendmailMTAAliasValue: ca@example.org 1983 sendmailMTAAliasValue: eric 1984 sendmailMTAAliasValue: gshapiro@example.com 1985 1986 dn: sendmailMTAKey=owner-sendmail-list, dc=sendmail, dc=org 1987 objectClass: sendmailMTA 1988 objectClass: sendmailMTAAlias 1989 objectClass: sendmailMTAAliasObject 1990 sendmailMTAAliasGrouping: aliases 1991 sendmailMTAHost: etrn.sendmail.org 1992 sendmailMTAKey: owner-sendmail-list 1993 sendmailMTAAliasValue: eric 1994 1995 dn: sendmailMTAKey=postmaster, dc=sendmail, dc=org 1996 objectClass: sendmailMTA 1997 objectClass: sendmailMTAAlias 1998 objectClass: sendmailMTAAliasObject 1999 sendmailMTAAliasGrouping: aliases 2000 sendmailMTACluster: Servers 2001 sendmailMTAKey: postmaster 2002 sendmailMTAAliasValue: eric 2003 2004Here, the aliases sendmail-list and owner-sendmail-list will be available 2005only on etrn.sendmail.org but the postmaster alias will be available on 2006every machine in the Servers cluster (including etrn.sendmail.org). 2007 2008CAUTION: aliases are additive so that entries like these: 2009 2010 dn: sendmailMTAKey=bob, dc=sendmail, dc=org 2011 objectClass: sendmailMTA 2012 objectClass: sendmailMTAAlias 2013 objectClass: sendmailMTAAliasObject 2014 sendmailMTAAliasGrouping: aliases 2015 sendmailMTACluster: Servers 2016 sendmailMTAKey: bob 2017 sendmailMTAAliasValue: eric 2018 2019 dn: sendmailMTAKey=bobetrn, dc=sendmail, dc=org 2020 objectClass: sendmailMTA 2021 objectClass: sendmailMTAAlias 2022 objectClass: sendmailMTAAliasObject 2023 sendmailMTAAliasGrouping: aliases 2024 sendmailMTAHost: etrn.sendmail.org 2025 sendmailMTAKey: bob 2026 sendmailMTAAliasValue: gshapiro 2027 2028would mean that on all of the hosts in the cluster, mail to bob would go to 2029eric EXCEPT on etrn.sendmail.org in which case it would go to BOTH eric and 2030gshapiro. 2031 2032If you prefer not to use the default LDAP schema for your aliases, you can 2033specify the map parameters when setting ALIAS_FILE. For example: 2034 2035 define(`ALIAS_FILE', `ldap:-k (&(objectClass=mailGroup)(mail=%0)) -v mgrpRFC822MailMember') 2036 2037---- 2038Maps 2039---- 2040 2041FEATURE()'s which take an optional map definition argument (e.g., access, 2042mailertable, virtusertable, etc.) can instead take the special keyword 2043`LDAP', e.g.: 2044 2045 FEATURE(`access_db', `LDAP') 2046 FEATURE(`virtusertable', `LDAP') 2047 2048When this keyword is given, that map will use LDAP lookups consisting of 2049the objectClass sendmailMTAClassObject, the attribute sendmailMTAMapName 2050with the map name, a search attribute of sendmailMTAKey, and the value 2051attribute sendmailMTAMapValue. 2052 2053The values for sendmailMTAMapName are: 2054 2055 FEATURE() sendmailMTAMapName 2056 --------- ------------------ 2057 access_db access 2058 authinfo authinfo 2059 bitdomain bitdomain 2060 domaintable domain 2061 genericstable generics 2062 mailertable mailer 2063 uucpdomain uucpdomain 2064 virtusertable virtuser 2065 2066For example, FEATURE(`mailertable', `LDAP') would use the map definition: 2067 2068 Kmailertable ldap -k (&(objectClass=sendmailMTAMapObject) 2069 (sendmailMTAMapName=mailer) 2070 (|(sendmailMTACluster=${sendmailMTACluster}) 2071 (sendmailMTAHost=$j)) 2072 (sendmailMTAKey=%0)) 2073 -1 -v sendmailMTAMapValue,sendmailMTAMapSearch:FILTER:sendmailMTAMapObject,sendmailMTAMapURL:URL:sendmailMTAMapObject 2074 2075An example LDAP LDIF entry using this map might be: 2076 2077 dn: sendmailMTAMapName=mailer, dc=sendmail, dc=org 2078 objectClass: sendmailMTA 2079 objectClass: sendmailMTAMap 2080 sendmailMTACluster: Servers 2081 sendmailMTAMapName: mailer 2082 2083 dn: sendmailMTAKey=example.com, sendmailMTAMapName=mailer, dc=sendmail, dc=org 2084 objectClass: sendmailMTA 2085 objectClass: sendmailMTAMap 2086 objectClass: sendmailMTAMapObject 2087 sendmailMTAMapName: mailer 2088 sendmailMTACluster: Servers 2089 sendmailMTAKey: example.com 2090 sendmailMTAMapValue: relay:[smtp.example.com] 2091 2092CAUTION: If your LDAP database contains the record above and *ALSO* a host 2093specific record such as: 2094 2095 dn: sendmailMTAKey=example.com@etrn, sendmailMTAMapName=mailer, dc=sendmail, dc=org 2096 objectClass: sendmailMTA 2097 objectClass: sendmailMTAMap 2098 objectClass: sendmailMTAMapObject 2099 sendmailMTAMapName: mailer 2100 sendmailMTAHost: etrn.sendmail.org 2101 sendmailMTAKey: example.com 2102 sendmailMTAMapValue: relay:[mx.example.com] 2103 2104then these entries will give unexpected results. When the lookup is done 2105on etrn.sendmail.org, the effect is that there is *NO* match at all as maps 2106require a single match. Since the host etrn.sendmail.org is also in the 2107Servers cluster, LDAP would return two answers for the example.com map key 2108in which case sendmail would treat this as no match at all. 2109 2110If you prefer not to use the default LDAP schema for your maps, you can 2111specify the map parameters when using the FEATURE(). For example: 2112 2113 FEATURE(`access_db', `ldap:-1 -k (&(objectClass=mapDatabase)(key=%0)) -v value') 2114 2115------- 2116Classes 2117------- 2118 2119Normally, classes can be filled via files or programs. As of 8.12, they 2120can also be filled via map lookups using a new syntax: 2121 2122 F{ClassName}mapkey@mapclass:mapspec 2123 2124mapkey is optional and if not provided the map key will be empty. This can 2125be used with LDAP to read classes from LDAP. Note that the lookup is only 2126done when sendmail is initially started. Use the special value `@LDAP' to 2127use the default LDAP schema. For example: 2128 2129 RELAY_DOMAIN_FILE(`@LDAP') 2130 2131would put all of the attribute sendmailMTAClassValue values of LDAP records 2132with objectClass sendmailMTAClass and an attribute sendmailMTAClassName of 2133'R' into class $={R}. In other words, it is equivalent to the LDAP map 2134specification: 2135 2136 F{R}@ldap:-k (&(objectClass=sendmailMTAClass) 2137 (sendmailMTAClassName=R) 2138 (|(sendmailMTACluster=${sendmailMTACluster}) 2139 (sendmailMTAHost=$j))) 2140 -v sendmailMTAClassValue,sendmailMTAClassSearch:FILTER:sendmailMTAClass,sendmailMTAClassURL:URL:sendmailMTAClass 2141 2142NOTE: The macros shown above ${sendmailMTACluster} and $j are not actually 2143used when the binary expands the `@LDAP' token as class declarations are 2144not actually macro-expanded when read from the sendmail.cf file. 2145 2146This can be used with class related commands such as RELAY_DOMAIN_FILE(), 2147MASQUERADE_DOMAIN_FILE(), etc: 2148 2149 Command sendmailMTAClassName 2150 ------- -------------------- 2151 CANONIFY_DOMAIN_FILE() Canonify 2152 EXPOSED_USER_FILE() E 2153 GENERICS_DOMAIN_FILE() G 2154 LDAPROUTE_DOMAIN_FILE() LDAPRoute 2155 LDAPROUTE_EQUIVALENT_FILE() LDAPRouteEquiv 2156 LOCAL_USER_FILE() L 2157 MASQUERADE_DOMAIN_FILE() M 2158 MASQUERADE_EXCEPTION_FILE() N 2159 RELAY_DOMAIN_FILE() R 2160 VIRTUSER_DOMAIN_FILE() VirtHost 2161 2162You can also add your own as any 'F'ile class of the form: 2163 2164 F{ClassName}@LDAP 2165 ^^^^^^^^^ 2166will use "ClassName" for the sendmailMTAClassName. 2167 2168An example LDAP LDIF entry would look like: 2169 2170 dn: sendmailMTAClassName=R, dc=sendmail, dc=org 2171 objectClass: sendmailMTA 2172 objectClass: sendmailMTAClass 2173 sendmailMTACluster: Servers 2174 sendmailMTAClassName: R 2175 sendmailMTAClassValue: sendmail.org 2176 sendmailMTAClassValue: example.com 2177 sendmailMTAClassValue: 10.56.23 2178 2179CAUTION: If your LDAP database contains the record above and *ALSO* a host 2180specific record such as: 2181 2182 dn: sendmailMTAClassName=R@etrn.sendmail.org, dc=sendmail, dc=org 2183 objectClass: sendmailMTA 2184 objectClass: sendmailMTAClass 2185 sendmailMTAHost: etrn.sendmail.org 2186 sendmailMTAClassName: R 2187 sendmailMTAClassValue: example.com 2188 2189the result will be similar to the aliases caution above. When the lookup 2190is done on etrn.sendmail.org, $={R} would contain all of the entries (from 2191both the cluster match and the host match). In other words, the effective 2192is additive. 2193 2194If you prefer not to use the default LDAP schema for your classes, you can 2195specify the map parameters when using the class command. For example: 2196 2197 VIRTUSER_DOMAIN_FILE(`@ldap:-k (&(objectClass=virtHosts)(host=*)) -v host') 2198 2199Remember, macros can not be used in a class declaration as the binary does 2200not expand them. 2201 2202 2203+--------------+ 2204| LDAP ROUTING | 2205+--------------+ 2206 2207FEATURE(`ldap_routing') can be used to implement the IETF Internet Draft 2208LDAP Schema for Intranet Mail Routing 2209(draft-lachman-laser-ldap-mail-routing-01). This feature enables 2210LDAP-based rerouting of a particular address to either a different host 2211or a different address. The LDAP lookup is first attempted on the full 2212address (e.g., user@example.com) and then on the domain portion 2213(e.g., @example.com). Be sure to setup your domain for LDAP routing using 2214LDAPROUTE_DOMAIN(), e.g.: 2215 2216 LDAPROUTE_DOMAIN(`example.com') 2217 2218Additionally, you can specify equivalent domains for LDAP routing using 2219LDAPROUTE_EQUIVALENT() and LDAPROUTE_EQUIVALENT_FILE(). 'Equivalent' 2220hostnames are mapped to $M (the masqueraded hostname for the server) before 2221the LDAP query. For example, if the mail is addressed to 2222user@host1.example.com, normally the LDAP lookup would only be done for 2223'user@host1.example.com' and '@host1.example.com'. However, if 2224LDAPROUTE_EQUIVALENT(`host1.example.com') is used, the lookups would also be 2225done on 'user@example.com' and '@example.com' after attempting the 2226host1.example.com lookups. 2227 2228By default, the feature will use the schemas as specified in the draft 2229and will not reject addresses not found by the LDAP lookup. However, 2230this behavior can be changed by giving additional arguments to the FEATURE() 2231command: 2232 2233 FEATURE(`ldap_routing', <mailHost>, <mailRoutingAddress>, <bounce>, 2234 <detail>, <nodomain>, <tempfail>) 2235 2236where <mailHost> is a map definition describing how to look up an alternative 2237mail host for a particular address; <mailRoutingAddress> is a map definition 2238describing how to look up an alternative address for a particular address; 2239the <bounce> argument, if present and not the word "passthru", dictates 2240that mail should be bounced if neither a mailHost nor mailRoutingAddress 2241is found, if set to "sendertoo", the sender will be rejected if not 2242found in LDAP; and <detail> indicates what actions to take if the address 2243contains +detail information -- `strip' tries the lookup with the +detail 2244and if no matches are found, strips the +detail and tries the lookup again; 2245`preserve', does the same as `strip' but if a mailRoutingAddress match is 2246found, the +detail information is copied to the new address; the <nodomain> 2247argument, if present, will prevent the @domain lookup if the full 2248address is not found in LDAP; the <tempfail> argument, if set to 2249"tempfail", instructs the rules to give an SMTP 4XX temporary 2250error if the LDAP server gives the MTA a temporary failure, or if set to 2251"queue" (the default), the MTA will locally queue the mail. 2252 2253The default <mailHost> map definition is: 2254 2255 ldap -1 -T<TMPF> -v mailHost -k (&(objectClass=inetLocalMailRecipient) 2256 (mailLocalAddress=%0)) 2257 2258The default <mailRoutingAddress> map definition is: 2259 2260 ldap -1 -T<TMPF> -v mailRoutingAddress 2261 -k (&(objectClass=inetLocalMailRecipient) 2262 (mailLocalAddress=%0)) 2263 2264Note that neither includes the LDAP server hostname (-h server) or base DN 2265(-b o=org,c=COUNTRY), both necessary for LDAP queries. It is presumed that 2266your .mc file contains a setting for the confLDAP_DEFAULT_SPEC option with 2267these settings. If this is not the case, the map definitions should be 2268changed as described above. The "-T<TMPF>" is required in any user 2269specified map definition to catch temporary errors. 2270 2271The following possibilities exist as a result of an LDAP lookup on an 2272address: 2273 2274 mailHost is mailRoutingAddress is Results in 2275 ----------- --------------------- ---------- 2276 set to a set mail delivered to 2277 "local" host mailRoutingAddress 2278 2279 set to a not set delivered to 2280 "local" host original address 2281 2282 set to a set mailRoutingAddress 2283 remote host relayed to mailHost 2284 2285 set to a not set original address 2286 remote host relayed to mailHost 2287 2288 not set set mail delivered to 2289 mailRoutingAddress 2290 2291 not set not set delivered to 2292 original address *OR* 2293 bounced as unknown user 2294 2295The term "local" host above means the host specified is in class {w}. If 2296the result would mean sending the mail to a different host, that host is 2297looked up in the mailertable before delivery. 2298 2299Note that the last case depends on whether the third argument is given 2300to the FEATURE() command. The default is to deliver the message to the 2301original address. 2302 2303The LDAP entries should be set up with an objectClass of 2304inetLocalMailRecipient and the address be listed in a mailLocalAddress 2305attribute. If present, there must be only one mailHost attribute and it 2306must contain a fully qualified host name as its value. Similarly, if 2307present, there must be only one mailRoutingAddress attribute and it must 2308contain an RFC 822 compliant address. Some example LDAP records (in LDIF 2309format): 2310 2311 dn: uid=tom, o=example.com, c=US 2312 objectClass: inetLocalMailRecipient 2313 mailLocalAddress: tom@example.com 2314 mailRoutingAddress: thomas@mailhost.example.com 2315 2316This would deliver mail for tom@example.com to thomas@mailhost.example.com. 2317 2318 dn: uid=dick, o=example.com, c=US 2319 objectClass: inetLocalMailRecipient 2320 mailLocalAddress: dick@example.com 2321 mailHost: eng.example.com 2322 2323This would relay mail for dick@example.com to the same address but redirect 2324the mail to MX records listed for the host eng.example.com (unless the 2325mailertable overrides). 2326 2327 dn: uid=harry, o=example.com, c=US 2328 objectClass: inetLocalMailRecipient 2329 mailLocalAddress: harry@example.com 2330 mailHost: mktmail.example.com 2331 mailRoutingAddress: harry@mkt.example.com 2332 2333This would relay mail for harry@example.com to the MX records listed for 2334the host mktmail.example.com using the new address harry@mkt.example.com 2335when talking to that host. 2336 2337 dn: uid=virtual.example.com, o=example.com, c=US 2338 objectClass: inetLocalMailRecipient 2339 mailLocalAddress: @virtual.example.com 2340 mailHost: server.example.com 2341 mailRoutingAddress: virtual@example.com 2342 2343This would send all mail destined for any username @virtual.example.com to 2344the machine server.example.com's MX servers and deliver to the address 2345virtual@example.com on that relay machine. 2346 2347 2348+---------------------------------+ 2349| ANTI-SPAM CONFIGURATION CONTROL | 2350+---------------------------------+ 2351 2352The primary anti-spam features available in sendmail are: 2353 2354* Relaying is denied by default. 2355* Better checking on sender information. 2356* Access database. 2357* Header checks. 2358 2359Relaying (transmission of messages from a site outside your host (class 2360{w}) to another site except yours) is denied by default. Note that this 2361changed in sendmail 8.9; previous versions allowed relaying by default. 2362If you really want to revert to the old behaviour, you will need to use 2363FEATURE(`promiscuous_relay'). You can allow certain domains to relay 2364through your server by adding their domain name or IP address to class 2365{R} using RELAY_DOMAIN() and RELAY_DOMAIN_FILE() or via the access database 2366(described below). Note that IPv6 addresses must be prefaced with "IPv6:". 2367The file consists (like any other file based class) of entries listed on 2368separate lines, e.g., 2369 2370 sendmail.org 2371 128.32 2372 IPv6:2002:c0a8:02c7 2373 IPv6:2002:c0a8:51d2::23f4 2374 host.mydomain.com 2375 [UNIX:localhost] 2376 2377Notice: the last entry allows relaying for connections via a UNIX 2378socket to the MTA/MSP. This might be necessary if your configuration 2379doesn't allow relaying by other means in that case, e.g., by having 2380localhost.$m in class {R} (make sure $m is not just a top level 2381domain). 2382 2383If you use 2384 2385 FEATURE(`relay_entire_domain') 2386 2387then any host in any of your local domains (that is, class {m}) 2388will be relayed (that is, you will accept mail either to or from any 2389host in your domain). 2390 2391You can also allow relaying based on the MX records of the host 2392portion of an incoming recipient address by using 2393 2394 FEATURE(`relay_based_on_MX') 2395 2396For example, if your server receives a recipient of user@domain.com 2397and domain.com lists your server in its MX records, the mail will be 2398accepted for relay to domain.com. This feature may cause problems 2399if MX lookups for the recipient domain are slow or time out. In that 2400case, mail will be temporarily rejected. It is usually better to 2401maintain a list of hosts/domains for which the server acts as relay. 2402Note also that this feature will stop spammers from using your host 2403to relay spam but it will not stop outsiders from using your server 2404as a relay for their site (that is, they set up an MX record pointing 2405to your mail server, and you will relay mail addressed to them 2406without any prior arrangement). Along the same lines, 2407 2408 FEATURE(`relay_local_from') 2409 2410will allow relaying if the sender specifies a return path (i.e. 2411MAIL FROM:<user@domain>) domain which is a local domain. This is a 2412dangerous feature as it will allow spammers to spam using your mail 2413server by simply specifying a return address of user@your.domain.com. 2414It should not be used unless absolutely necessary. 2415A slightly better solution is 2416 2417 FEATURE(`relay_mail_from') 2418 2419which allows relaying if the mail sender is listed as RELAY in the 2420access map. If an optional argument `domain' (this is the literal 2421word `domain', not a placeholder) is given, the domain portion of 2422the mail sender is also checked to allowing relaying. This option 2423only works together with the tag From: for the LHS of the access 2424map entries. This feature allows spammers to abuse your mail server 2425by specifying a return address that you enabled in your access file. 2426This may be harder to figure out for spammers, but it should not 2427be used unless necessary. Instead use SMTP AUTH or STARTTLS to 2428allow relaying for roaming users. 2429 2430 2431If source routing is used in the recipient address (e.g., 2432RCPT TO:<user%site.com@othersite.com>), sendmail will check 2433user@site.com for relaying if othersite.com is an allowed relay host 2434in either class {R}, class {m} if FEATURE(`relay_entire_domain') is used, 2435or the access database if FEATURE(`access_db') is used. To prevent 2436the address from being stripped down, use: 2437 2438 FEATURE(`loose_relay_check') 2439 2440If you think you need to use this feature, you probably do not. This 2441should only be used for sites which have no control over the addresses 2442that they provide a gateway for. Use this FEATURE with caution as it 2443can allow spammers to relay through your server if not setup properly. 2444 2445NOTICE: It is possible to relay mail through a system which the anti-relay 2446rules do not prevent: the case of a system that does use FEATURE(`nouucp', 2447`nospecial') (system A) and relays local messages to a mail hub (e.g., via 2448LOCAL_RELAY or LUSER_RELAY) (system B). If system B doesn't use 2449FEATURE(`nouucp') at all, addresses of the form 2450<example.net!user@local.host> would be relayed to <user@example.net>. 2451System A doesn't recognize `!' as an address separator and therefore 2452forwards it to the mail hub which in turns relays it because it came from 2453a trusted local host. So if a mailserver allows UUCP (bang-format) 2454addresses, all systems from which it allows relaying should do the same 2455or reject those addresses. 2456 2457As of 8.9, sendmail will refuse mail if the MAIL FROM: parameter has 2458an unresolvable domain (i.e., one that DNS, your local name service, 2459or special case rules in ruleset 3 cannot locate). This also applies 2460to addresses that use domain literals, e.g., <user@[1.2.3.4]>, if the 2461IP address can't be mapped to a host name. If you want to continue 2462to accept such domains, e.g., because you are inside a firewall that 2463has only a limited view of the Internet host name space (note that you 2464will not be able to return mail to them unless you have some "smart 2465host" forwarder), use 2466 2467 FEATURE(`accept_unresolvable_domains') 2468 2469Alternatively, you can allow specific addresses by adding them to 2470the access map, e.g., 2471 2472 From:unresolvable.domain OK 2473 From:[1.2.3.4] OK 2474 From:[1.2.4] OK 2475 2476Notice: domains which are temporarily unresolvable are (temporarily) 2477rejected with a 451 reply code. If those domains should be accepted 2478(which is discouraged) then you can use 2479 2480 LOCAL_CONFIG 2481 C{ResOk}TEMP 2482 2483sendmail will also refuse mail if the MAIL FROM: parameter is not 2484fully qualified (i.e., contains a domain as well as a user). If you 2485want to continue to accept such senders, use 2486 2487 FEATURE(`accept_unqualified_senders') 2488 2489Setting the DaemonPortOptions modifier 'u' overrides the default behavior, 2490i.e., unqualified addresses are accepted even without this FEATURE. If 2491this FEATURE is not used, the DaemonPortOptions modifier 'f' can be used 2492to enforce fully qualified domain names. 2493 2494An ``access'' database can be created to accept or reject mail from 2495selected domains. For example, you may choose to reject all mail 2496originating from known spammers. To enable such a database, use 2497 2498 FEATURE(`access_db') 2499 2500Notice: the access database is applied to the envelope addresses 2501and the connection information, not to the header. 2502 2503The FEATURE macro can accept as second parameter the key file 2504definition for the database; for example 2505 2506 FEATURE(`access_db', `hash -T<TMPF> /etc/mail/access_map') 2507 2508Notice: If a second argument is specified it must contain the option 2509`-T<TMPF>' as shown above. The optional parameters may be 2510 2511 `skip' enables SKIP as value part (see below). 2512 `lookupdotdomain' another way to enable the feature of the 2513 same name (see above). 2514 `relaytofulladdress' enable entries of the form 2515 To:user@example.com RELAY 2516 to allow relaying to just a specific 2517 e-mail address instead of an entire domain. 2518 2519Remember, since /etc/mail/access is a database, after creating the text 2520file as described below, you must use makemap to create the database 2521map. For example: 2522 2523 makemap hash /etc/mail/access < /etc/mail/access 2524 2525The table itself uses e-mail addresses, domain names, and network 2526numbers as keys. Note that IPv6 addresses must be prefaced with "IPv6:". 2527For example, 2528 2529 From:spammer@aol.com REJECT 2530 From:cyberspammer.com REJECT 2531 Connect:cyberspammer.com REJECT 2532 Connect:TLD REJECT 2533 Connect:192.168.212 REJECT 2534 Connect:IPv6:2002:c0a8:02c7 RELAY 2535 Connect:IPv6:2002:c0a8:51d2::23f4 REJECT 2536 2537would refuse mail from spammer@aol.com, any user from cyberspammer.com 2538(or any host within the cyberspammer.com domain), any host in the entire 2539top level domain TLD, 192.168.212.* network, and the IPv6 address 25402002:c0a8:51d2::23f4. It would allow relay for the IPv6 network 25412002:c0a8:02c7::/48. 2542 2543Entries in the access map should be tagged according to their type. 2544Three tags are available: 2545 2546 Connect: connection information (${client_addr}, ${client_name}) 2547 From: envelope sender 2548 To: envelope recipient 2549 2550Notice: untagged entries are deprecated. 2551 2552If the required item is looked up in a map, it will be tried first 2553with the corresponding tag in front, then (as fallback to enable 2554backward compatibility) without any tag, unless the specific feature 2555requires a tag. For example, 2556 2557 From:spammer@some.dom REJECT 2558 To:friend.domain RELAY 2559 Connect:friend.domain OK 2560 Connect:from.domain RELAY 2561 From:good@another.dom OK 2562 From:another.dom REJECT 2563 2564This would deny mails from spammer@some.dom but you could still 2565send mail to that address even if FEATURE(`blacklist_recipients') 2566is enabled. Your system will allow relaying to friend.domain, but 2567not from it (unless enabled by other means). Connections from that 2568domain will be allowed even if it ends up in one of the DNS based 2569rejection lists. Relaying is enabled from from.domain but not to 2570it (since relaying is based on the connection information for 2571outgoing relaying, the tag Connect: must be used; for incoming 2572relaying, which is based on the recipient address, To: must be 2573used). The last two entries allow mails from good@another.dom but 2574reject mail from all other addresses with another.dom as domain 2575part. 2576 2577 2578The value part of the map can contain: 2579 2580 OK Accept mail even if other rules in the running 2581 ruleset would reject it, for example, if the domain 2582 name is unresolvable. "Accept" does not mean 2583 "relay", but at most acceptance for local 2584 recipients. That is, OK allows less than RELAY. 2585 RELAY Accept mail addressed to the indicated domain 2586 (or address if `relaytofulladdress' is set) or 2587 received from the indicated domain for relaying 2588 through your SMTP server. RELAY also serves as 2589 an implicit OK for the other checks. 2590 REJECT Reject the sender or recipient with a general 2591 purpose message. 2592 DISCARD Discard the message completely using the 2593 $#discard mailer. If it is used in check_compat, 2594 it affects only the designated recipient, not 2595 the whole message as it does in all other cases. 2596 This should only be used if really necessary. 2597 SKIP This can only be used for host/domain names 2598 and IP addresses/nets. It will abort the current 2599 search for this entry without accepting or rejecting 2600 it but causing the default action. 2601 ### any text where ### is an RFC 821 compliant error code and 2602 "any text" is a message to return for the command. 2603 The entire string should be quoted to avoid 2604 surprises: 2605 2606 "### any text" 2607 2608 Otherwise sendmail formats the text as email 2609 addresses, e.g., it may remove spaces. 2610 This type is deprecated, use one of the two 2611 ERROR: entries below instead. 2612 ERROR:### any text 2613 as above, but useful to mark error messages as such. 2614 If quotes need to be used to avoid modifications 2615 (see above), they should be placed like this: 2616 2617 ERROR:"### any text" 2618 2619 ERROR:D.S.N:### any text 2620 where D.S.N is an RFC 1893 compliant error code 2621 and the rest as above. If quotes need to be used 2622 to avoid modifications, they should be placed 2623 like this: 2624 2625 ERROR:D.S.N:"### any text" 2626 2627 QUARANTINE:any text 2628 Quarantine the message using the given text as the 2629 quarantining reason. 2630 2631For example: 2632 2633 From:cyberspammer.com ERROR:"550 We don't accept mail from spammers" 2634 From:okay.cyberspammer.com OK 2635 Connect:sendmail.org RELAY 2636 To:sendmail.org RELAY 2637 Connect:128.32 RELAY 2638 Connect:128.32.2 SKIP 2639 Connect:IPv6:1:2:3:4:5:6:7 RELAY 2640 Connect:suspicious.example.com QUARANTINE:Mail from suspicious host 2641 Connect:[127.0.0.3] OK 2642 Connect:[IPv6:1:2:3:4:5:6:7:8] OK 2643 2644would accept mail from okay.cyberspammer.com, but would reject mail 2645from all other hosts at cyberspammer.com with the indicated message. 2646It would allow relaying mail from and to any hosts in the sendmail.org 2647domain, and allow relaying from the IPv6 1:2:3:4:5:6:7:* network 2648and from the 128.32.*.* network except for the 128.32.2.* network, 2649which shows how SKIP is useful to exempt subnets/subdomains. The 2650last two entries are for checks against ${client_name} if the IP 2651address doesn't resolve to a hostname (or is considered as "may be 2652forged"). That is, using square brackets means these are host 2653names, not network numbers. 2654 2655Warning: if you change the RFC 821 compliant error code from the default 2656value of 550, then you should probably also change the RFC 1893 compliant 2657error code to match it. For example, if you use 2658 2659 To:user@example.com ERROR:450 mailbox full 2660 2661the error returned would be "450 5.0.0 mailbox full" which is wrong. 2662Use "ERROR:4.2.2:450 mailbox full" instead. 2663 2664Note, UUCP users may need to add hostname.UUCP to the access database 2665or class {R}. 2666 2667If you also use: 2668 2669 FEATURE(`relay_hosts_only') 2670 2671then the above example will allow relaying for sendmail.org, but not 2672hosts within the sendmail.org domain. Note that this will also require 2673hosts listed in class {R} to be fully qualified host names. 2674 2675You can also use the access database to block sender addresses based on 2676the username portion of the address. For example: 2677 2678 From:FREE.STEALTH.MAILER@ ERROR:550 Spam not accepted 2679 2680Note that you must include the @ after the username to signify that 2681this database entry is for checking only the username portion of the 2682sender address. 2683 2684If you use: 2685 2686 FEATURE(`blacklist_recipients') 2687 2688then you can add entries to the map for local users, hosts in your 2689domains, or addresses in your domain which should not receive mail: 2690 2691 To:badlocaluser@ ERROR:550 Mailbox disabled for badlocaluser 2692 To:host.my.TLD ERROR:550 That host does not accept mail 2693 To:user@other.my.TLD ERROR:550 Mailbox disabled for this recipient 2694 2695This would prevent a recipient of badlocaluser in any of the local 2696domains (class {w}), any user at host.my.TLD, and the single address 2697user@other.my.TLD from receiving mail. Please note: a local username 2698must be now tagged with an @ (this is consistent with the check of 2699the sender address, and hence it is possible to distinguish between 2700hostnames and usernames). Enabling this feature will keep you from 2701sending mails to all addresses that have an error message or REJECT 2702as value part in the access map. Taking the example from above: 2703 2704 spammer@aol.com REJECT 2705 cyberspammer.com REJECT 2706 2707Mail can't be sent to spammer@aol.com or anyone at cyberspammer.com. 2708That's why tagged entries should be used. 2709 2710There are several DNS based blacklists which can be found by 2711querying a search engine. These are databases of spammers 2712maintained in DNS. To use such a database, specify 2713 2714 FEATURE(`dnsbl', `dnsbl.example.com') 2715 2716This will cause sendmail to reject mail from any site listed in the 2717DNS based blacklist. You must select a DNS based blacklist domain 2718to check by specifying an argument to the FEATURE. The default 2719error message is 2720 2721 Rejected: IP-ADDRESS listed at SERVER 2722 2723where IP-ADDRESS and SERVER are replaced by the appropriate 2724information. A second argument can be used to specify a different 2725text or action. For example, 2726 2727 FEATURE(`dnsbl', `dnsbl.example.com', `quarantine') 2728 2729would quarantine the message if the client IP address is listed 2730at `dnsbl.example.com'. 2731 2732By default, temporary lookup failures are ignored 2733and hence cause the connection not to be rejected by the DNS based 2734rejection list. This behavior can be changed by specifying a third 2735argument, which must be either `t' or a full error message. For 2736example: 2737 2738 FEATURE(`dnsbl', `dnsbl.example.com', `', 2739 `"451 Temporary lookup failure for " $&{client_addr} " in dnsbl.example.com"') 2740 2741If `t' is used, the error message is: 2742 2743 451 Temporary lookup failure of IP-ADDRESS at SERVER 2744 2745where IP-ADDRESS and SERVER are replaced by the appropriate 2746information. 2747 2748This FEATURE can be included several times to query different 2749DNS based rejection lists. 2750 2751Notice: to avoid checking your own local domains against those 2752blacklists, use the access_db feature and add: 2753 2754 Connect:10.1 OK 2755 Connect:127.0.0.1 RELAY 2756 2757to the access map, where 10.1 is your local network. You may 2758want to use "RELAY" instead of "OK" to allow also relaying 2759instead of just disabling the DNS lookups in the blacklists. 2760 2761 2762The features described above make use of the check_relay, check_mail, 2763and check_rcpt rulesets. Note that check_relay checks the SMTP 2764client hostname and IP address when the connection is made to your 2765server. It does not check if a mail message is being relayed to 2766another server. That check is done in check_rcpt. If you wish to 2767include your own checks, you can put your checks in the rulesets 2768Local_check_relay, Local_check_mail, and Local_check_rcpt. For 2769example if you wanted to block senders with all numeric usernames 2770(i.e. 2312343@bigisp.com), you would use Local_check_mail and the 2771regex map: 2772 2773 LOCAL_CONFIG 2774 Kallnumbers regex -a@MATCH ^[0-9]+$ 2775 2776 LOCAL_RULESETS 2777 SLocal_check_mail 2778 # check address against various regex checks 2779 R$* $: $>Parse0 $>3 $1 2780 R$+ < @ bigisp.com. > $* $: $(allnumbers $1 $) 2781 R@MATCH $#error $: 553 Header Error 2782 2783These rules are called with the original arguments of the corresponding 2784check_* ruleset. If the local ruleset returns $#OK, no further checking 2785is done by the features described above and the mail is accepted. If 2786the local ruleset resolves to a mailer (such as $#error or $#discard), 2787the appropriate action is taken. Other results starting with $# are 2788interpreted by sendmail and may lead to unspecified behavior. Note: do 2789NOT create a mailer with the name OK. Return values that do not start 2790with $# are ignored, i.e., normal processing continues. 2791 2792Delay all checks 2793---------------- 2794 2795By using FEATURE(`delay_checks') the rulesets check_mail and check_relay 2796will not be called when a client connects or issues a MAIL command, 2797respectively. Instead, those rulesets will be called by the check_rcpt 2798ruleset; they will be skipped if a sender has been authenticated using 2799a "trusted" mechanism, i.e., one that is defined via TRUST_AUTH_MECH(). 2800If check_mail returns an error then the RCPT TO command will be rejected 2801with that error. If it returns some other result starting with $# then 2802check_relay will be skipped. If the sender address (or a part of it) is 2803listed in the access map and it has a RHS of OK or RELAY, then check_relay 2804will be skipped. This has an interesting side effect: if your domain is 2805my.domain and you have 2806 2807 my.domain RELAY 2808 2809in the access map, then any e-mail with a sender address of 2810<user@my.domain> will not be rejected by check_relay even though 2811it would match the hostname or IP address. This allows spammers 2812to get around DNS based blacklist by faking the sender address. To 2813avoid this problem you have to use tagged entries: 2814 2815 To:my.domain RELAY 2816 Connect:my.domain RELAY 2817 2818if you need those entries at all (class {R} may take care of them). 2819 2820FEATURE(`delay_checks') can take an optional argument: 2821 2822 FEATURE(`delay_checks', `friend') 2823 enables spamfriend test 2824 FEATURE(`delay_checks', `hater') 2825 enables spamhater test 2826 2827If such an argument is given, the recipient will be looked up in the 2828access map (using the tag Spam:). If the argument is `friend', then 2829the default behavior is to apply the other rulesets and make a SPAM 2830friend the exception. The rulesets check_mail and check_relay will be 2831skipped only if the recipient address is found and has RHS FRIEND. If 2832the argument is `hater', then the default behavior is to skip the rulesets 2833check_mail and check_relay and make a SPAM hater the exception. The 2834other two rulesets will be applied only if the recipient address is 2835found and has RHS HATER. 2836 2837This allows for simple exceptions from the tests, e.g., by activating 2838the friend option and having 2839 2840 Spam:abuse@ FRIEND 2841 2842in the access map, mail to abuse@localdomain will get through (where 2843"localdomain" is any domain in class {w}). It is also possible to 2844specify a full address or an address with +detail: 2845 2846 Spam:abuse@my.domain FRIEND 2847 Spam:me+abuse@ FRIEND 2848 Spam:spam.domain FRIEND 2849 2850Note: The required tag has been changed in 8.12 from To: to Spam:. 2851This change is incompatible to previous versions. However, you can 2852(for now) simply add the new entries to the access map, the old 2853ones will be ignored. As soon as you removed the old entries from 2854the access map, specify a third parameter (`n') to this feature and 2855the backward compatibility rules will not be in the generated .cf 2856file. 2857 2858Header Checks 2859------------- 2860 2861You can also reject mail on the basis of the contents of headers. 2862This is done by adding a ruleset call to the 'H' header definition command 2863in sendmail.cf. For example, this can be used to check the validity of 2864a Message-ID: header: 2865 2866 LOCAL_CONFIG 2867 HMessage-Id: $>CheckMessageId 2868 2869 LOCAL_RULESETS 2870 SCheckMessageId 2871 R< $+ @ $+ > $@ OK 2872 R$* $#error $: 553 Header Error 2873 2874The alternative format: 2875 2876 HSubject: $>+CheckSubject 2877 2878that is, $>+ instead of $>, gives the full Subject: header including 2879comments to the ruleset (comments in parentheses () are stripped 2880by default). 2881 2882A default ruleset for headers which don't have a specific ruleset 2883defined for them can be given by: 2884 2885 H*: $>CheckHdr 2886 2887Notice: 28881. All rules act on tokens as explained in doc/op/op.{me,ps,txt}. 2889That may cause problems with simple header checks due to the 2890tokenization. It might be simpler to use a regex map and apply it 2891to $&{currHeader}. 28922. There are no default rulesets coming with this distribution of 2893sendmail. You can write your own, can search the WWW for examples, 2894or take a look at cf/cf/knecht.mc. 28953. When using a default ruleset for headers, the name of the header 2896currently being checked can be found in the $&{hdr_name} macro. 2897 2898After all of the headers are read, the check_eoh ruleset will be called for 2899any final header-related checks. The ruleset is called with the number of 2900headers and the size of all of the headers in bytes separated by $|. One 2901example usage is to reject messages which do not have a Message-Id: 2902header. However, the Message-Id: header is *NOT* a required header and is 2903not a guaranteed spam indicator. This ruleset is an example and should 2904probably not be used in production. 2905 2906 LOCAL_CONFIG 2907 Kstorage macro 2908 HMessage-Id: $>CheckMessageId 2909 2910 LOCAL_RULESETS 2911 SCheckMessageId 2912 # Record the presence of the header 2913 R$* $: $(storage {MessageIdCheck} $@ OK $) $1 2914 R< $+ @ $+ > $@ OK 2915 R$* $#error $: 553 Header Error 2916 2917 Scheck_eoh 2918 # Check the macro 2919 R$* $: < $&{MessageIdCheck} > 2920 # Clear the macro for the next message 2921 R$* $: $(storage {MessageIdCheck} $) $1 2922 # Has a Message-Id: header 2923 R< $+ > $@ OK 2924 # Allow missing Message-Id: from local mail 2925 R$* $: < $&{client_name} > 2926 R< > $@ OK 2927 R< $=w > $@ OK 2928 # Otherwise, reject the mail 2929 R$* $#error $: 553 Header Error 2930 2931 2932+--------------------+ 2933| CONNECTION CONTROL | 2934+--------------------+ 2935 2936The features ratecontrol and conncontrol allow to establish connection 2937limits per client IP address or net. These features can limit the 2938rate of connections (connections per time unit) or the number of 2939incoming SMTP connections, respectively. If enabled, appropriate 2940rulesets are called at the end of check_relay, i.e., after DNS 2941blacklists and generic access_db operations. The features require 2942FEATURE(`access_db') to be listed earlier in the mc file. 2943 2944Note: FEATURE(`delay_checks') delays those connection control checks 2945after a recipient address has been received, hence making these 2946connection control features less useful. To run the checks as early 2947as possible, specify the parameter `nodelay', e.g., 2948 2949 FEATURE(`ratecontrol', `nodelay') 2950 2951In that case, FEATURE(`delay_checks') has no effect on connection 2952control (and it must be specified earlier in the mc file). 2953 2954An optional second argument `terminate' specifies whether the 2955rulesets should return the error code 421 which will cause 2956sendmail to terminate the session with that error if it is 2957returned from check_relay, i.e., not delayed as explained in 2958the previous paragraph. Example: 2959 2960 FEATURE(`ratecontrol', `nodelay', `terminate') 2961 2962 2963+----------+ 2964| STARTTLS | 2965+----------+ 2966 2967In this text, cert will be used as an abbreviation for X.509 certificate, 2968DN (CN) is the distinguished (common) name of a cert, and CA is a 2969certification authority, which signs (issues) certs. 2970 2971For STARTTLS to be offered by sendmail you need to set at least 2972these variables (the file names and paths are just examples): 2973 2974 define(`confCACERT_PATH', `/etc/mail/certs/') 2975 define(`confCACERT', `/etc/mail/certs/CA.cert.pem') 2976 define(`confSERVER_CERT', `/etc/mail/certs/my.cert.pem') 2977 define(`confSERVER_KEY', `/etc/mail/certs/my.key.pem') 2978 2979On systems which do not have the compile flag HASURANDOM set (see 2980sendmail/README) you also must set confRAND_FILE. 2981 2982See doc/op/op.{me,ps,txt} for more information about these options, 2983especially the sections ``Certificates for STARTTLS'' and ``PRNG for 2984STARTTLS''. 2985 2986Macros related to STARTTLS are: 2987 2988${cert_issuer} holds the DN of the CA (the cert issuer). 2989${cert_subject} holds the DN of the cert (called the cert subject). 2990${cn_issuer} holds the CN of the CA (the cert issuer). 2991${cn_subject} holds the CN of the cert (called the cert subject). 2992${tls_version} the TLS/SSL version used for the connection, e.g., TLSv1, 2993 TLSv1/SSLv3, SSLv3, SSLv2. 2994${cipher} the cipher used for the connection, e.g., EDH-DSS-DES-CBC3-SHA, 2995 EDH-RSA-DES-CBC-SHA, DES-CBC-MD5, DES-CBC3-SHA. 2996${cipher_bits} the keylength (in bits) of the symmetric encryption algorithm 2997 used for the connection. 2998${verify} holds the result of the verification of the presented cert. 2999 Possible values are: 3000 OK verification succeeded. 3001 NO no cert presented. 3002 NOT no cert requested. 3003 FAIL cert presented but could not be verified, 3004 e.g., the cert of the signing CA is missing. 3005 NONE STARTTLS has not been performed. 3006 TEMP temporary error occurred. 3007 PROTOCOL protocol error occurred (SMTP level). 3008 SOFTWARE STARTTLS handshake failed. 3009${server_name} the name of the server of the current outgoing SMTP 3010 connection. 3011${server_addr} the address of the server of the current outgoing SMTP 3012 connection. 3013 3014Relaying 3015-------- 3016 3017SMTP STARTTLS can allow relaying for remote SMTP clients which have 3018successfully authenticated themselves. If the verification of the cert 3019failed (${verify} != OK), relaying is subject to the usual rules. 3020Otherwise the DN of the issuer is looked up in the access map using the 3021tag CERTISSUER. If the resulting value is RELAY, relaying is allowed. 3022If it is SUBJECT, the DN of the cert subject is looked up next in the 3023access map using the tag CERTSUBJECT. If the value is RELAY, relaying 3024is allowed. 3025 3026To make things a bit more flexible (or complicated), the values for 3027${cert_issuer} and ${cert_subject} can be optionally modified by regular 3028expressions defined in the m4 variables _CERT_REGEX_ISSUER_ and 3029_CERT_REGEX_SUBJECT_, respectively. To avoid problems with those macros in 3030rulesets and map lookups, they are modified as follows: each non-printable 3031character and the characters '<', '>', '(', ')', '"', '+', ' ' are replaced 3032by their HEX value with a leading '+'. For example: 3033 3034/C=US/ST=California/O=endmail.org/OU=private/CN=Darth Mail (Cert)/Email= 3035darth+cert@endmail.org 3036 3037is encoded as: 3038 3039/C=US/ST=California/O=endmail.org/OU=private/CN= 3040Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org 3041 3042(line breaks have been inserted for readability). 3043 3044The macros which are subject to this encoding are ${cert_subject}, 3045${cert_issuer}, ${cn_subject}, and ${cn_issuer}. 3046 3047Examples: 3048 3049To allow relaying for everyone who can present a cert signed by 3050 3051/C=US/ST=California/O=endmail.org/OU=private/CN= 3052Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org 3053 3054simply use: 3055 3056CertIssuer:/C=US/ST=California/O=endmail.org/OU=private/CN= 3057Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org RELAY 3058 3059To allow relaying only for a subset of machines that have a cert signed by 3060 3061/C=US/ST=California/O=endmail.org/OU=private/CN= 3062Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org 3063 3064use: 3065 3066CertIssuer:/C=US/ST=California/O=endmail.org/OU=private/CN= 3067Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org SUBJECT 3068CertSubject:/C=US/ST=California/O=endmail.org/OU=private/CN= 3069DeathStar/Email=deathstar@endmail.org RELAY 3070 3071Notes: 3072- line breaks have been inserted after "CN=" for readability, 3073 each tagged entry must be one (long) line in the access map. 3074- if OpenSSL 0.9.7 or newer is used then the "Email=" part of a DN 3075 is replaced by "emailAddress=". 3076 3077Of course it is also possible to write a simple ruleset that allows 3078relaying for everyone who can present a cert that can be verified, e.g., 3079 3080LOCAL_RULESETS 3081SLocal_check_rcpt 3082R$* $: $&{verify} 3083ROK $# OK 3084 3085Allowing Connections 3086-------------------- 3087 3088The rulesets tls_server, tls_client, and tls_rcpt are used to decide whether 3089an SMTP connection is accepted (or should continue). 3090 3091tls_server is called when sendmail acts as client after a STARTTLS command 3092(should) have been issued. The parameter is the value of ${verify}. 3093 3094tls_client is called when sendmail acts as server, after a STARTTLS command 3095has been issued, and from check_mail. The parameter is the value of 3096${verify} and STARTTLS or MAIL, respectively. 3097 3098Both rulesets behave the same. If no access map is in use, the connection 3099will be accepted unless ${verify} is SOFTWARE, in which case the connection 3100is always aborted. For tls_server/tls_client, ${client_name}/${server_name} 3101is looked up in the access map using the tag TLS_Srv/TLS_Clt, which is done 3102with the ruleset LookUpDomain. If no entry is found, ${client_addr} 3103(${server_addr}) is looked up in the access map (same tag, ruleset 3104LookUpAddr). If this doesn't result in an entry either, just the tag is 3105looked up in the access map (included the trailing colon). Notice: 3106requiring that e-mail is sent to a server only encrypted, e.g., via 3107 3108TLS_Srv:secure.domain ENCR:112 3109 3110doesn't necessarily mean that e-mail sent to that domain is encrypted. 3111If the domain has multiple MX servers, e.g., 3112 3113secure.domain. IN MX 10 mail.secure.domain. 3114secure.domain. IN MX 50 mail.other.domain. 3115 3116then mail to user@secure.domain may go unencrypted to mail.other.domain. 3117tls_rcpt can be used to address this problem. 3118 3119tls_rcpt is called before a RCPT TO: command is sent. The parameter is the 3120current recipient. This ruleset is only defined if FEATURE(`access_db') 3121is selected. A recipient address user@domain is looked up in the access 3122map in four formats: TLS_Rcpt:user@domain, TLS_Rcpt:user@, TLS_Rcpt:domain, 3123and TLS_Rcpt:; the first match is taken. 3124 3125The result of the lookups is then used to call the ruleset TLS_connection, 3126which checks the requirement specified by the RHS in the access map against 3127the actual parameters of the current TLS connection, esp. ${verify} and 3128${cipher_bits}. Legal RHSs in the access map are: 3129 3130VERIFY verification must have succeeded 3131VERIFY:bits verification must have succeeded and ${cipher_bits} must 3132 be greater than or equal bits. 3133ENCR:bits ${cipher_bits} must be greater than or equal bits. 3134 3135The RHS can optionally be prefixed by TEMP+ or PERM+ to select a temporary 3136or permanent error. The default is a temporary error code (403 4.7.0) 3137unless the macro TLS_PERM_ERR is set during generation of the .cf file. 3138 3139If a certain level of encryption is required, then it might also be 3140possible that this level is provided by the security layer from a SASL 3141algorithm, e.g., DIGEST-MD5. 3142 3143Furthermore, there can be a list of extensions added. Such a list 3144starts with '+' and the items are separated by '++'. Allowed 3145extensions are: 3146 3147CN:name name must match ${cn_subject} 3148CN ${client_name}/${server_name} must match ${cn_subject} 3149CS:name name must match ${cert_subject} 3150CI:name name must match ${cert_issuer} 3151 3152Example: e-mail sent to secure.example.com should only use an encrypted 3153connection. E-mail received from hosts within the laptop.example.com domain 3154should only be accepted if they have been authenticated. The host which 3155receives e-mail for darth@endmail.org must present a cert that uses the 3156CN smtp.endmail.org. 3157 3158TLS_Srv:secure.example.com ENCR:112 3159TLS_Clt:laptop.example.com PERM+VERIFY:112 3160TLS_Rcpt:darth@endmail.org ENCR:112+CN:smtp.endmail.org 3161 3162 3163Disabling STARTTLS And Setting SMTP Server Features 3164--------------------------------------------------- 3165 3166By default STARTTLS is used whenever possible. However, there are 3167some broken MTAs that don't properly implement STARTTLS. To be able 3168to send to (or receive from) those MTAs, the ruleset try_tls 3169(srv_features) can be used that work together with the access map. 3170Entries for the access map must be tagged with Try_TLS (Srv_Features) 3171and refer to the hostname or IP address of the connecting system. 3172A default case can be specified by using just the tag. For example, 3173the following entries in the access map: 3174 3175 Try_TLS:broken.server NO 3176 Srv_Features:my.domain v 3177 Srv_Features: V 3178 3179will turn off STARTTLS when sending to broken.server (or any host 3180in that domain), and request a client certificate during the TLS 3181handshake only for hosts in my.domain. The valid entries on the RHS 3182for Srv_Features are listed in the Sendmail Installation and 3183Operations Guide. 3184 3185 3186Received: Header 3187---------------- 3188 3189The Received: header reveals whether STARTTLS has been used. It contains an 3190extra line: 3191 3192(version=${tls_version} cipher=${cipher} bits=${cipher_bits} verify=${verify}) 3193 3194 3195+---------------------+ 3196| SMTP AUTHENTICATION | 3197+---------------------+ 3198 3199The macros ${auth_authen}, ${auth_author}, and ${auth_type} can be 3200used in anti-relay rulesets to allow relaying for those users that 3201authenticated themselves. A very simple example is: 3202 3203SLocal_check_rcpt 3204R$* $: $&{auth_type} 3205R$+ $# OK 3206 3207which checks whether a user has successfully authenticated using 3208any available mechanism. Depending on the setup of the Cyrus SASL 3209library, more sophisticated rulesets might be required, e.g., 3210 3211SLocal_check_rcpt 3212R$* $: $&{auth_type} $| $&{auth_authen} 3213RDIGEST-MD5 $| $+@$=w $# OK 3214 3215to allow relaying for users that authenticated using DIGEST-MD5 3216and have an identity in the local domains. 3217 3218The ruleset trust_auth is used to determine whether a given AUTH= 3219parameter (that is passed to this ruleset) should be trusted. This 3220ruleset may make use of the other ${auth_*} macros. Only if the 3221ruleset resolves to the error mailer, the AUTH= parameter is not 3222trusted. A user supplied ruleset Local_trust_auth can be written 3223to modify the default behavior, which only trust the AUTH= 3224parameter if it is identical to the authenticated user. 3225 3226Per default, relaying is allowed for any user who authenticated 3227via a "trusted" mechanism, i.e., one that is defined via 3228TRUST_AUTH_MECH(`list of mechanisms') 3229For example: 3230TRUST_AUTH_MECH(`KERBEROS_V4 DIGEST-MD5') 3231 3232If the selected mechanism provides a security layer the number of 3233bits used for the key of the symmetric cipher is stored in the 3234macro ${auth_ssf}. 3235 3236Providing SMTP AUTH Data when sendmail acts as Client 3237----------------------------------------------------- 3238 3239If sendmail acts as client, it needs some information how to 3240authenticate against another MTA. This information can be provided 3241by the ruleset authinfo or by the option DefaultAuthInfo. The 3242authinfo ruleset looks up {server_name} using the tag AuthInfo: in 3243the access map. If no entry is found, {server_addr} is looked up 3244in the same way and finally just the tag AuthInfo: to provide 3245default values. Note: searches for domain parts or IP nets are 3246only performed if the access map is used; if the authinfo feature 3247is used then only up to three lookups are performed (two exact 3248matches, one default). 3249 3250Note: If your daemon does client authentication when sending, and 3251if it uses either PLAIN or LOGIN authentication, then you *must* 3252prevent ordinary users from seeing verbose output. Do NOT install 3253sendmail set-user-ID. Use PrivacyOptions to turn off verbose output 3254("goaway" works for this). 3255 3256Notice: the default configuration file causes the option DefaultAuthInfo 3257to fail since the ruleset authinfo is in the .cf file. If you really 3258want to use DefaultAuthInfo (it is deprecated) then you have to 3259remove the ruleset. 3260 3261The RHS for an AuthInfo: entry in the access map should consists of a 3262list of tokens, each of which has the form: "TDstring" (including 3263the quotes). T is a tag which describes the item, D is a delimiter, 3264either ':' for simple text or '=' for a base64 encoded string. 3265Valid values for the tag are: 3266 3267 U user (authorization) id 3268 I authentication id 3269 P password 3270 R realm 3271 M list of mechanisms delimited by spaces 3272 3273Example entries are: 3274 3275AuthInfo:other.dom "U:user" "I:user" "P:secret" "R:other.dom" "M:DIGEST-MD5" 3276AuthInfo:host.more.dom "U:user" "P=c2VjcmV0" 3277 3278User id or authentication id must exist as well as the password. All 3279other entries have default values. If one of user or authentication 3280id is missing, the existing value is used for the missing item. 3281If "R:" is not specified, realm defaults to $j. The list of mechanisms 3282defaults to those specified by AuthMechanisms. 3283 3284Since this map contains sensitive information, either the access 3285map must be unreadable by everyone but root (or the trusted user) 3286or FEATURE(`authinfo') must be used which provides a separate map. 3287Notice: It is not checked whether the map is actually 3288group/world-unreadable, this is left to the user. 3289 3290+--------------------------------+ 3291| ADDING NEW MAILERS OR RULESETS | 3292+--------------------------------+ 3293 3294Sometimes you may need to add entirely new mailers or rulesets. They 3295should be introduced with the constructs MAILER_DEFINITIONS and 3296LOCAL_RULESETS respectively. For example: 3297 3298 MAILER_DEFINITIONS 3299 Mmymailer, ... 3300 ... 3301 3302 LOCAL_RULESETS 3303 Smyruleset 3304 ... 3305 3306Local additions for the rulesets srv_features, try_tls, tls_rcpt, 3307tls_client, and tls_server can be made using LOCAL_SRV_FEATURES, 3308LOCAL_TRY_TLS, LOCAL_TLS_RCPT, LOCAL_TLS_CLIENT, and LOCAL_TLS_SERVER, 3309respectively. For example, to add a local ruleset that decides 3310whether to try STARTTLS in a sendmail client, use: 3311 3312 LOCAL_TRY_TLS 3313 R... 3314 3315Note: you don't need to add a name for the ruleset, it is implicitly 3316defined by using the appropriate macro. 3317 3318 3319+-------------------------+ 3320| ADDING NEW MAIL FILTERS | 3321+-------------------------+ 3322 3323Sendmail supports mail filters to filter incoming SMTP messages according 3324to the "Sendmail Mail Filter API" documentation. These filters can be 3325configured in your mc file using the two commands: 3326 3327 MAIL_FILTER(`name', `equates') 3328 INPUT_MAIL_FILTER(`name', `equates') 3329 3330The first command, MAIL_FILTER(), simply defines a filter with the given 3331name and equates. For example: 3332 3333 MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R') 3334 3335This creates the equivalent sendmail.cf entry: 3336 3337 Xarchive, S=local:/var/run/archivesock, F=R 3338 3339The INPUT_MAIL_FILTER() command performs the same actions as MAIL_FILTER 3340but also populates the m4 variable `confINPUT_MAIL_FILTERS' with the name 3341of the filter such that the filter will actually be called by sendmail. 3342 3343For example, the two commands: 3344 3345 INPUT_MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R') 3346 INPUT_MAIL_FILTER(`spamcheck', `S=inet:2525@localhost, F=T') 3347 3348are equivalent to the three commands: 3349 3350 MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R') 3351 MAIL_FILTER(`spamcheck', `S=inet:2525@localhost, F=T') 3352 define(`confINPUT_MAIL_FILTERS', `archive, spamcheck') 3353 3354In general, INPUT_MAIL_FILTER() should be used unless you need to define 3355more filters than you want to use for `confINPUT_MAIL_FILTERS'. 3356 3357Note that setting `confINPUT_MAIL_FILTERS' after any INPUT_MAIL_FILTER() 3358commands will clear the list created by the prior INPUT_MAIL_FILTER() 3359commands. 3360 3361 3362+-------------------------+ 3363| QUEUE GROUP DEFINITIONS | 3364+-------------------------+ 3365 3366In addition to the queue directory (which is the default queue group 3367called "mqueue"), sendmail can deal with multiple queue groups, which 3368are collections of queue directories with the same behaviour. Queue 3369groups can be defined using the command: 3370 3371 QUEUE_GROUP(`name', `equates') 3372 3373For details about queue groups, please see doc/op/op.{me,ps,txt}. 3374 3375+-------------------------------+ 3376| NON-SMTP BASED CONFIGURATIONS | 3377+-------------------------------+ 3378 3379These configuration files are designed primarily for use by 3380SMTP-based sites. They may not be well tuned for UUCP-only or 3381UUCP-primarily nodes (the latter is defined as a small local net 3382connected to the rest of the world via UUCP). However, there is 3383one hook to handle some special cases. 3384 3385You can define a ``smart host'' that understands a richer address syntax 3386using: 3387 3388 define(`SMART_HOST', `mailer:hostname') 3389 3390In this case, the ``mailer:'' defaults to "relay". Any messages that 3391can't be handled using the usual UUCP rules are passed to this host. 3392 3393If you are on a local SMTP-based net that connects to the outside 3394world via UUCP, you can use LOCAL_NET_CONFIG to add appropriate rules. 3395For example: 3396 3397 define(`SMART_HOST', `uucp-new:uunet') 3398 LOCAL_NET_CONFIG 3399 R$* < @ $* .$m. > $* $#smtp $@ $2.$m. $: $1 < @ $2.$m. > $3 3400 3401This will cause all names that end in your domain name ($m) to be sent 3402via SMTP; anything else will be sent via uucp-new (smart UUCP) to uunet. 3403If you have FEATURE(`nocanonify'), you may need to omit the dots after 3404the $m. If you are running a local DNS inside your domain which is 3405not otherwise connected to the outside world, you probably want to 3406use: 3407 3408 define(`SMART_HOST', `smtp:fire.wall.com') 3409 LOCAL_NET_CONFIG 3410 R$* < @ $* . > $* $#smtp $@ $2. $: $1 < @ $2. > $3 3411 3412That is, send directly only to things you found in your DNS lookup; 3413anything else goes through SMART_HOST. 3414 3415You may need to turn off the anti-spam rules in order to accept 3416UUCP mail with FEATURE(`promiscuous_relay') and 3417FEATURE(`accept_unresolvable_domains'). 3418 3419 3420+-----------+ 3421| WHO AM I? | 3422+-----------+ 3423 3424Normally, the $j macro is automatically defined to be your fully 3425qualified domain name (FQDN). Sendmail does this by getting your 3426host name using gethostname and then calling gethostbyname on the 3427result. For example, in some environments gethostname returns 3428only the root of the host name (such as "foo"); gethostbyname is 3429supposed to return the FQDN ("foo.bar.com"). In some (fairly rare) 3430cases, gethostbyname may fail to return the FQDN. In this case 3431you MUST define confDOMAIN_NAME to be your fully qualified domain 3432name. This is usually done using: 3433 3434 Dmbar.com 3435 define(`confDOMAIN_NAME', `$w.$m')dnl 3436 3437 3438+-----------------------------------+ 3439| ACCEPTING MAIL FOR MULTIPLE NAMES | 3440+-----------------------------------+ 3441 3442If your host is known by several different names, you need to augment 3443class {w}. This is a list of names by which your host is known, and 3444anything sent to an address using a host name in this list will be 3445treated as local mail. You can do this in two ways: either create the 3446file /etc/mail/local-host-names containing a list of your aliases (one per 3447line), and use ``FEATURE(`use_cw_file')'' in the .mc file, or add 3448``LOCAL_DOMAIN(`alias.host.name')''. Be sure you use the fully-qualified 3449name of the host, rather than a short name. 3450 3451If you want to have different address in different domains, take 3452a look at the virtusertable feature, which is also explained at 3453http://www.sendmail.org/virtual-hosting.html 3454 3455 3456+--------------------+ 3457| USING MAILERTABLES | 3458+--------------------+ 3459 3460To use FEATURE(`mailertable'), you will have to create an external 3461database containing the routing information for various domains. 3462For example, a mailertable file in text format might be: 3463 3464 .my.domain xnet:%1.my.domain 3465 uuhost1.my.domain uucp-new:uuhost1 3466 .bitnet smtp:relay.bit.net 3467 3468This should normally be stored in /etc/mail/mailertable. The actual 3469database version of the mailertable is built using: 3470 3471 makemap hash /etc/mail/mailertable < /etc/mail/mailertable 3472 3473The semantics are simple. Any LHS entry that does not begin with 3474a dot matches the full host name indicated. LHS entries beginning 3475with a dot match anything ending with that domain name (including 3476the leading dot) -- that is, they can be thought of as having a 3477leading ".+" regular expression pattern for a non-empty sequence of 3478characters. Matching is done in order of most-to-least qualified 3479-- for example, even though ".my.domain" is listed first in the 3480above example, an entry of "uuhost1.my.domain" will match the second 3481entry since it is more explicit. Note: e-mail to "user@my.domain" 3482does not match any entry in the above table. You need to have 3483something like: 3484 3485 my.domain esmtp:host.my.domain 3486 3487The RHS should always be a "mailer:host" pair. The mailer is the 3488configuration name of a mailer (that is, an M line in the 3489sendmail.cf file). The "host" will be the hostname passed to 3490that mailer. In domain-based matches (that is, those with leading 3491dots) the "%1" may be used to interpolate the wildcarded part of 3492the host name. For example, the first line above sends everything 3493addressed to "anything.my.domain" to that same host name, but using 3494the (presumably experimental) xnet mailer. 3495 3496In some cases you may want to temporarily turn off MX records, 3497particularly on gateways. For example, you may want to MX 3498everything in a domain to one machine that then forwards it 3499directly. To do this, you might use the DNS configuration: 3500 3501 *.domain. IN MX 0 relay.machine 3502 3503and on relay.machine use the mailertable: 3504 3505 .domain smtp:[gateway.domain] 3506 3507The [square brackets] turn off MX records for this host only. 3508If you didn't do this, the mailertable would use the MX record 3509again, which would give you an MX loop. Note that the use of 3510wildcard MX records is almost always a bad idea. Please avoid 3511using them if possible. 3512 3513 3514+--------------------------------+ 3515| USING USERDB TO MAP FULL NAMES | 3516+--------------------------------+ 3517 3518The user database was not originally intended for mapping full names 3519to login names (e.g., Eric.Allman => eric), but some people are using 3520it that way. (it is recommended that you set up aliases for this 3521purpose instead -- since you can specify multiple alias files, this 3522is fairly easy.) The intent was to locate the default maildrop at 3523a site, but allow you to override this by sending to a specific host. 3524 3525If you decide to set up the user database in this fashion, it is 3526imperative that you not use FEATURE(`stickyhost') -- otherwise, 3527e-mail sent to Full.Name@local.host.name will be rejected. 3528 3529To build the internal form of the user database, use: 3530 3531 makemap btree /etc/mail/userdb < /etc/mail/userdb.txt 3532 3533As a general rule, it is an extremely bad idea to using full names 3534as e-mail addresses, since they are not in any sense unique. For 3535example, the UNIX software-development community has at least two 3536well-known Peter Deutsches, and at one time Bell Labs had two 3537Stephen R. Bournes with offices along the same hallway. Which one 3538will be forced to suffer the indignity of being Stephen_R_Bourne_2? 3539The less famous of the two, or the one that was hired later? 3540 3541Finger should handle full names (and be fuzzy). Mail should use 3542handles, and not be fuzzy. 3543 3544 3545+--------------------------------+ 3546| MISCELLANEOUS SPECIAL FEATURES | 3547+--------------------------------+ 3548 3549Plussed users 3550 Sometimes it is convenient to merge configuration on a 3551 centralized mail machine, for example, to forward all 3552 root mail to a mail server. In this case it might be 3553 useful to be able to treat the root addresses as a class 3554 of addresses with subtle differences. You can do this 3555 using plussed users. For example, a client might include 3556 the alias: 3557 3558 root: root+client1@server 3559 3560 On the server, this will match an alias for "root+client1". 3561 If that is not found, the alias "root+*" will be tried, 3562 then "root". 3563 3564 3565+----------------+ 3566| SECURITY NOTES | 3567+----------------+ 3568 3569A lot of sendmail security comes down to you. Sendmail 8 is much 3570more careful about checking for security problems than previous 3571versions, but there are some things that you still need to watch 3572for. In particular: 3573 3574* Make sure the aliases file is not writable except by trusted 3575 system personnel. This includes both the text and database 3576 version. 3577 3578* Make sure that other files that sendmail reads, such as the 3579 mailertable, are only writable by trusted system personnel. 3580 3581* The queue directory should not be world writable PARTICULARLY 3582 if your system allows "file giveaways" (that is, if a non-root 3583 user can chown any file they own to any other user). 3584 3585* If your system allows file giveaways, DO NOT create a publically 3586 writable directory for forward files. This will allow anyone 3587 to steal anyone else's e-mail. Instead, create a script that 3588 copies the .forward file from users' home directories once a 3589 night (if you want the non-NFS-mounted forward directory). 3590 3591* If your system allows file giveaways, you'll find that 3592 sendmail is much less trusting of :include: files -- in 3593 particular, you'll have to have /SENDMAIL/ANY/SHELL/ in 3594 /etc/shells before they will be trusted (that is, before 3595 files and programs listed in them will be honored). 3596 3597In general, file giveaways are a mistake -- if you can turn them 3598off, do so. 3599 3600 3601+--------------------------------+ 3602| TWEAKING CONFIGURATION OPTIONS | 3603+--------------------------------+ 3604 3605There are a large number of configuration options that don't normally 3606need to be changed. However, if you feel you need to tweak them, 3607you can define the following M4 variables. Note that some of these 3608variables require formats that are defined in RFC 2821 or RFC 2822. 3609Before changing them you need to make sure you do not violate those 3610(and other relevant) RFCs. 3611 3612This list is shown in four columns: the name you define, the default 3613value for that definition, the option or macro that is affected 3614(either Ox for an option or Dx for a macro), and a brief description. 3615Greater detail of the semantics can be found in the Installation 3616and Operations Guide. 3617 3618Some options are likely to be deprecated in future versions -- that is, 3619the option is only included to provide back-compatibility. These are 3620marked with "*". 3621 3622Remember that these options are M4 variables, and hence may need to 3623be quoted. In particular, arguments with commas will usually have to 3624be ``double quoted, like this phrase'' to avoid having the comma 3625confuse things. This is common for alias file definitions and for 3626the read timeout. 3627 3628M4 Variable Name Configuration [Default] & Description 3629================ ============= ======================= 3630confMAILER_NAME $n macro [MAILER-DAEMON] The sender name used 3631 for internally generated outgoing 3632 messages. 3633confDOMAIN_NAME $j macro If defined, sets $j. This should 3634 only be done if your system cannot 3635 determine your local domain name, 3636 and then it should be set to 3637 $w.Foo.COM, where Foo.COM is your 3638 domain name. 3639confCF_VERSION $Z macro If defined, this is appended to the 3640 configuration version name. 3641confLDAP_CLUSTER ${sendmailMTACluster} macro 3642 If defined, this is the LDAP 3643 cluster to use for LDAP searches 3644 as described above in ``USING LDAP 3645 FOR ALIASES, MAPS, AND CLASSES''. 3646confFROM_HEADER From: [$?x$x <$g>$|$g$.] The format of an 3647 internally generated From: address. 3648confRECEIVED_HEADER Received: 3649 [$?sfrom $s $.$?_($?s$|from $.$_) 3650 $.$?{auth_type}(authenticated) 3651 $.by $j ($v/$Z)$?r with $r$. id $i$?u 3652 for $u; $|; 3653 $.$b] 3654 The format of the Received: header 3655 in messages passed through this host. 3656 It is unwise to try to change this. 3657confMESSAGEID_HEADER Message-Id: [<$t.$i@$j>] The format of an 3658 internally generated Message-Id: 3659 header. 3660confCW_FILE Fw class [/etc/mail/local-host-names] Name 3661 of file used to get the local 3662 additions to class {w} (local host 3663 names). 3664confCT_FILE Ft class [/etc/mail/trusted-users] Name of 3665 file used to get the local additions 3666 to class {t} (trusted users). 3667confCR_FILE FR class [/etc/mail/relay-domains] Name of 3668 file used to get the local additions 3669 to class {R} (hosts allowed to relay). 3670confTRUSTED_USERS Ct class [no default] Names of users to add to 3671 the list of trusted users. This list 3672 always includes root, uucp, and daemon. 3673 See also FEATURE(`use_ct_file'). 3674confTRUSTED_USER TrustedUser [no default] Trusted user for file 3675 ownership and starting the daemon. 3676 Not to be confused with 3677 confTRUSTED_USERS (see above). 3678confSMTP_MAILER - [esmtp] The mailer name used when 3679 SMTP connectivity is required. 3680 One of "smtp", "smtp8", 3681 "esmtp", or "dsmtp". 3682confUUCP_MAILER - [uucp-old] The mailer to be used by 3683 default for bang-format recipient 3684 addresses. See also discussion of 3685 class {U}, class {Y}, and class {Z} 3686 in the MAILER(`uucp') section. 3687confLOCAL_MAILER - [local] The mailer name used when 3688 local connectivity is required. 3689 Almost always "local". 3690confRELAY_MAILER - [relay] The default mailer name used 3691 for relaying any mail (e.g., to a 3692 BITNET_RELAY, a SMART_HOST, or 3693 whatever). This can reasonably be 3694 "uucp-new" if you are on a 3695 UUCP-connected site. 3696confSEVEN_BIT_INPUT SevenBitInput [False] Force input to seven bits? 3697confEIGHT_BIT_HANDLING EightBitMode [pass8] 8-bit data handling 3698confALIAS_WAIT AliasWait [10m] Time to wait for alias file 3699 rebuild until you get bored and 3700 decide that the apparently pending 3701 rebuild failed. 3702confMIN_FREE_BLOCKS MinFreeBlocks [100] Minimum number of free blocks on 3703 queue filesystem to accept SMTP mail. 3704 (Prior to 8.7 this was minfree/maxsize, 3705 where minfree was the number of free 3706 blocks and maxsize was the maximum 3707 message size. Use confMAX_MESSAGE_SIZE 3708 for the second value now.) 3709confMAX_MESSAGE_SIZE MaxMessageSize [infinite] The maximum size of messages 3710 that will be accepted (in bytes). 3711confBLANK_SUB BlankSub [.] Blank (space) substitution 3712 character. 3713confCON_EXPENSIVE HoldExpensive [False] Avoid connecting immediately 3714 to mailers marked expensive. 3715confCHECKPOINT_INTERVAL CheckpointInterval 3716 [10] Checkpoint queue files every N 3717 recipients. 3718confDELIVERY_MODE DeliveryMode [background] Default delivery mode. 3719confERROR_MODE ErrorMode [print] Error message mode. 3720confERROR_MESSAGE ErrorHeader [undefined] Error message header/file. 3721confSAVE_FROM_LINES SaveFromLine Save extra leading From_ lines. 3722confTEMP_FILE_MODE TempFileMode [0600] Temporary file mode. 3723confMATCH_GECOS MatchGECOS [False] Match GECOS field. 3724confMAX_HOP MaxHopCount [25] Maximum hop count. 3725confIGNORE_DOTS* IgnoreDots [False; always False in -bs or -bd 3726 mode] Ignore dot as terminator for 3727 incoming messages? 3728confBIND_OPTS ResolverOptions [undefined] Default options for DNS 3729 resolver. 3730confMIME_FORMAT_ERRORS* SendMimeErrors [True] Send error messages as MIME- 3731 encapsulated messages per RFC 1344. 3732confFORWARD_PATH ForwardPath [$z/.forward.$w:$z/.forward] 3733 The colon-separated list of places to 3734 search for .forward files. N.B.: see 3735 the Security Notes section. 3736confMCI_CACHE_SIZE ConnectionCacheSize 3737 [2] Size of open connection cache. 3738confMCI_CACHE_TIMEOUT ConnectionCacheTimeout 3739 [5m] Open connection cache timeout. 3740confHOST_STATUS_DIRECTORY HostStatusDirectory 3741 [undefined] If set, host status is kept 3742 on disk between sendmail runs in the 3743 named directory tree. This need not be 3744 a full pathname, in which case it is 3745 interpreted relative to the queue 3746 directory. 3747confSINGLE_THREAD_DELIVERY SingleThreadDelivery 3748 [False] If this option and the 3749 HostStatusDirectory option are both 3750 set, single thread deliveries to other 3751 hosts. That is, don't allow any two 3752 sendmails on this host to connect 3753 simultaneously to any other single 3754 host. This can slow down delivery in 3755 some cases, in particular since a 3756 cached but otherwise idle connection 3757 to a host will prevent other sendmails 3758 from connecting to the other host. 3759confUSE_ERRORS_TO* UseErrorsTo [False] Use the Errors-To: header to 3760 deliver error messages. This should 3761 not be necessary because of general 3762 acceptance of the envelope/header 3763 distinction. 3764confLOG_LEVEL LogLevel [9] Log level. 3765confME_TOO MeToo [True] Include sender in group 3766 expansions. This option is 3767 deprecated and will be removed from 3768 a future version. 3769confCHECK_ALIASES CheckAliases [False] Check RHS of aliases when 3770 running newaliases. Since this does 3771 DNS lookups on every address, it can 3772 slow down the alias rebuild process 3773 considerably on large alias files. 3774confOLD_STYLE_HEADERS* OldStyleHeaders [True] Assume that headers without 3775 special chars are old style. 3776confPRIVACY_FLAGS PrivacyOptions [authwarnings] Privacy flags. 3777confCOPY_ERRORS_TO PostmasterCopy [undefined] Address for additional 3778 copies of all error messages. 3779confQUEUE_FACTOR QueueFactor [600000] Slope of queue-only function. 3780confQUEUE_FILE_MODE QueueFileMode [undefined] Default permissions for 3781 queue files (octal). If not set, 3782 sendmail uses 0600 unless its real 3783 and effective uid are different in 3784 which case it uses 0644. 3785confDONT_PRUNE_ROUTES DontPruneRoutes [False] Don't prune down route-addr 3786 syntax addresses to the minimum 3787 possible. 3788confSAFE_QUEUE* SuperSafe [True] Commit all messages to disk 3789 before forking. 3790confTO_INITIAL Timeout.initial [5m] The timeout waiting for a response 3791 on the initial connect. 3792confTO_CONNECT Timeout.connect [0] The timeout waiting for an initial 3793 connect() to complete. This can only 3794 shorten connection timeouts; the kernel 3795 silently enforces an absolute maximum 3796 (which varies depending on the system). 3797confTO_ICONNECT Timeout.iconnect 3798 [undefined] Like Timeout.connect, but 3799 applies only to the very first attempt 3800 to connect to a host in a message. 3801 This allows a single very fast pass 3802 followed by more careful delivery 3803 attempts in the future. 3804confTO_ACONNECT Timeout.aconnect 3805 [0] The overall timeout waiting for 3806 all connection for a single delivery 3807 attempt to succeed. If 0, no overall 3808 limit is applied. 3809confTO_HELO Timeout.helo [5m] The timeout waiting for a response 3810 to a HELO or EHLO command. 3811confTO_MAIL Timeout.mail [10m] The timeout waiting for a 3812 response to the MAIL command. 3813confTO_RCPT Timeout.rcpt [1h] The timeout waiting for a response 3814 to the RCPT command. 3815confTO_DATAINIT Timeout.datainit 3816 [5m] The timeout waiting for a 354 3817 response from the DATA command. 3818confTO_DATABLOCK Timeout.datablock 3819 [1h] The timeout waiting for a block 3820 during DATA phase. 3821confTO_DATAFINAL Timeout.datafinal 3822 [1h] The timeout waiting for a response 3823 to the final "." that terminates a 3824 message. 3825confTO_RSET Timeout.rset [5m] The timeout waiting for a response 3826 to the RSET command. 3827confTO_QUIT Timeout.quit [2m] The timeout waiting for a response 3828 to the QUIT command. 3829confTO_MISC Timeout.misc [2m] The timeout waiting for a response 3830 to other SMTP commands. 3831confTO_COMMAND Timeout.command [1h] In server SMTP, the timeout 3832 waiting for a command to be issued. 3833confTO_IDENT Timeout.ident [5s] The timeout waiting for a 3834 response to an IDENT query. 3835confTO_FILEOPEN Timeout.fileopen 3836 [60s] The timeout waiting for a file 3837 (e.g., :include: file) to be opened. 3838confTO_LHLO Timeout.lhlo [2m] The timeout waiting for a response 3839 to an LMTP LHLO command. 3840confTO_AUTH Timeout.auth [10m] The timeout waiting for a 3841 response in an AUTH dialogue. 3842confTO_STARTTLS Timeout.starttls 3843 [1h] The timeout waiting for a 3844 response to an SMTP STARTTLS command. 3845confTO_CONTROL Timeout.control 3846 [2m] The timeout for a complete 3847 control socket transaction to complete. 3848confTO_QUEUERETURN Timeout.queuereturn 3849 [5d] The timeout before a message is 3850 returned as undeliverable. 3851confTO_QUEUERETURN_NORMAL 3852 Timeout.queuereturn.normal 3853 [undefined] As above, for normal 3854 priority messages. 3855confTO_QUEUERETURN_URGENT 3856 Timeout.queuereturn.urgent 3857 [undefined] As above, for urgent 3858 priority messages. 3859confTO_QUEUERETURN_NONURGENT 3860 Timeout.queuereturn.non-urgent 3861 [undefined] As above, for non-urgent 3862 (low) priority messages. 3863confTO_QUEUERETURN_DSN 3864 Timeout.queuereturn.dsn 3865 [undefined] As above, for delivery 3866 status notification messages. 3867confTO_QUEUEWARN Timeout.queuewarn 3868 [4h] The timeout before a warning 3869 message is sent to the sender telling 3870 them that the message has been 3871 deferred. 3872confTO_QUEUEWARN_NORMAL Timeout.queuewarn.normal 3873 [undefined] As above, for normal 3874 priority messages. 3875confTO_QUEUEWARN_URGENT Timeout.queuewarn.urgent 3876 [undefined] As above, for urgent 3877 priority messages. 3878confTO_QUEUEWARN_NONURGENT 3879 Timeout.queuewarn.non-urgent 3880 [undefined] As above, for non-urgent 3881 (low) priority messages. 3882confTO_QUEUEWARN_DSN 3883 Timeout.queuewarn.dsn 3884 [undefined] As above, for delivery 3885 status notification messages. 3886confTO_HOSTSTATUS Timeout.hoststatus 3887 [30m] How long information about host 3888 statuses will be maintained before it 3889 is considered stale and the host should 3890 be retried. This applies both within 3891 a single queue run and to persistent 3892 information (see below). 3893confTO_RESOLVER_RETRANS Timeout.resolver.retrans 3894 [varies] Sets the resolver's 3895 retransmission time interval (in 3896 seconds). Sets both 3897 Timeout.resolver.retrans.first and 3898 Timeout.resolver.retrans.normal. 3899confTO_RESOLVER_RETRANS_FIRST Timeout.resolver.retrans.first 3900 [varies] Sets the resolver's 3901 retransmission time interval (in 3902 seconds) for the first attempt to 3903 deliver a message. 3904confTO_RESOLVER_RETRANS_NORMAL Timeout.resolver.retrans.normal 3905 [varies] Sets the resolver's 3906 retransmission time interval (in 3907 seconds) for all resolver lookups 3908 except the first delivery attempt. 3909confTO_RESOLVER_RETRY Timeout.resolver.retry 3910 [varies] Sets the number of times 3911 to retransmit a resolver query. 3912 Sets both 3913 Timeout.resolver.retry.first and 3914 Timeout.resolver.retry.normal. 3915confTO_RESOLVER_RETRY_FIRST Timeout.resolver.retry.first 3916 [varies] Sets the number of times 3917 to retransmit a resolver query for 3918 the first attempt to deliver a 3919 message. 3920confTO_RESOLVER_RETRY_NORMAL Timeout.resolver.retry.normal 3921 [varies] Sets the number of times 3922 to retransmit a resolver query for 3923 all resolver lookups except the 3924 first delivery attempt. 3925confTIME_ZONE TimeZoneSpec [USE_SYSTEM] Time zone info -- can be 3926 USE_SYSTEM to use the system's idea, 3927 USE_TZ to use the user's TZ envariable, 3928 or something else to force that value. 3929confDEF_USER_ID DefaultUser [1:1] Default user id. 3930confUSERDB_SPEC UserDatabaseSpec 3931 [undefined] User database 3932 specification. 3933confFALLBACK_MX FallbackMXhost [undefined] Fallback MX host. 3934confFALLBACK_SMARTHOST FallbackSmartHost 3935 [undefined] Fallback smart host. 3936confTRY_NULL_MX_LIST TryNullMXList [False] If this host is the best MX 3937 for a host and other arrangements 3938 haven't been made, try connecting 3939 to the host directly; normally this 3940 would be a config error. 3941confQUEUE_LA QueueLA [varies] Load average at which 3942 queue-only function kicks in. 3943 Default values is (8 * numproc) 3944 where numproc is the number of 3945 processors online (if that can be 3946 determined). 3947confREFUSE_LA RefuseLA [varies] Load average at which 3948 incoming SMTP connections are 3949 refused. Default values is (12 * 3950 numproc) where numproc is the 3951 number of processors online (if 3952 that can be determined). 3953confREJECT_LOG_INTERVAL RejectLogInterval [3h] Log interval when 3954 refusing connections for this long. 3955confDELAY_LA DelayLA [0] Load average at which sendmail 3956 will sleep for one second on most 3957 SMTP commands and before accepting 3958 connections. 0 means no limit. 3959confMAX_ALIAS_RECURSION MaxAliasRecursion 3960 [10] Maximum depth of alias recursion. 3961confMAX_DAEMON_CHILDREN MaxDaemonChildren 3962 [undefined] The maximum number of 3963 children the daemon will permit. After 3964 this number, connections will be 3965 rejected. If not set or <= 0, there is 3966 no limit. 3967confMAX_HEADERS_LENGTH MaxHeadersLength 3968 [32768] Maximum length of the sum 3969 of all headers. 3970confMAX_MIME_HEADER_LENGTH MaxMimeHeaderLength 3971 [undefined] Maximum length of 3972 certain MIME header field values. 3973confCONNECTION_RATE_THROTTLE ConnectionRateThrottle 3974 [undefined] The maximum number of 3975 connections permitted per second per 3976 daemon. After this many connections 3977 are accepted, further connections 3978 will be delayed. If not set or <= 0, 3979 there is no limit. 3980confCONNECTION_RATE_WINDOW_SIZE ConnectionRateWindowSize 3981 [60s] Define the length of the 3982 interval for which the number of 3983 incoming connections is maintained. 3984confWORK_RECIPIENT_FACTOR 3985 RecipientFactor [30000] Cost of each recipient. 3986confSEPARATE_PROC ForkEachJob [False] Run all deliveries in a 3987 separate process. 3988confWORK_CLASS_FACTOR ClassFactor [1800] Priority multiplier for class. 3989confWORK_TIME_FACTOR RetryFactor [90000] Cost of each delivery attempt. 3990confQUEUE_SORT_ORDER QueueSortOrder [Priority] Queue sort algorithm: 3991 Priority, Host, Filename, Random, 3992 Modification, or Time. 3993confMIN_QUEUE_AGE MinQueueAge [0] The minimum amount of time a job 3994 must sit in the queue between queue 3995 runs. This allows you to set the 3996 queue run interval low for better 3997 responsiveness without trying all 3998 jobs in each run. 3999confDEF_CHAR_SET DefaultCharSet [unknown-8bit] When converting 4000 unlabeled 8 bit input to MIME, the 4001 character set to use by default. 4002confSERVICE_SWITCH_FILE ServiceSwitchFile 4003 [/etc/mail/service.switch] The file 4004 to use for the service switch on 4005 systems that do not have a 4006 system-defined switch. 4007confHOSTS_FILE HostsFile [/etc/hosts] The file to use when doing 4008 "file" type access of hosts names. 4009confDIAL_DELAY DialDelay [0s] If a connection fails, wait this 4010 long and try again. Zero means "don't 4011 retry". This is to allow "dial on 4012 demand" connections to have enough time 4013 to complete a connection. 4014confNO_RCPT_ACTION NoRecipientAction 4015 [none] What to do if there are no legal 4016 recipient fields (To:, Cc: or Bcc:) 4017 in the message. Legal values can 4018 be "none" to just leave the 4019 nonconforming message as is, "add-to" 4020 to add a To: header with all the 4021 known recipients (which may expose 4022 blind recipients), "add-apparently-to" 4023 to do the same but use Apparently-To: 4024 instead of To: (strongly discouraged 4025 in accordance with IETF standards), 4026 "add-bcc" to add an empty Bcc: 4027 header, or "add-to-undisclosed" to 4028 add the header 4029 ``To: undisclosed-recipients:;''. 4030confSAFE_FILE_ENV SafeFileEnvironment 4031 [undefined] If set, sendmail will do a 4032 chroot() into this directory before 4033 writing files. 4034confCOLON_OK_IN_ADDR ColonOkInAddr [True unless Configuration Level > 6] 4035 If set, colons are treated as a regular 4036 character in addresses. If not set, 4037 they are treated as the introducer to 4038 the RFC 822 "group" syntax. Colons are 4039 handled properly in route-addrs. This 4040 option defaults on for V5 and lower 4041 configuration files. 4042confMAX_QUEUE_RUN_SIZE MaxQueueRunSize [0] If set, limit the maximum size of 4043 any given queue run to this number of 4044 entries. Essentially, this will stop 4045 reading each queue directory after this 4046 number of entries are reached; it does 4047 _not_ pick the highest priority jobs, 4048 so this should be as large as your 4049 system can tolerate. If not set, there 4050 is no limit. 4051confMAX_QUEUE_CHILDREN MaxQueueChildren 4052 [undefined] Limits the maximum number 4053 of concurrent queue runners active. 4054 This is to keep system resources used 4055 within a reasonable limit. Relates to 4056 Queue Groups and ForkEachJob. 4057confMAX_RUNNERS_PER_QUEUE MaxRunnersPerQueue 4058 [1] Only active when MaxQueueChildren 4059 defined. Controls the maximum number 4060 of queue runners (aka queue children) 4061 active at the same time in a work 4062 group. See also MaxQueueChildren. 4063confDONT_EXPAND_CNAMES DontExpandCnames 4064 [False] If set, $[ ... $] lookups that 4065 do DNS based lookups do not expand 4066 CNAME records. This currently violates 4067 the published standards, but the IETF 4068 seems to be moving toward legalizing 4069 this. For example, if "FTP.Foo.ORG" 4070 is a CNAME for "Cruft.Foo.ORG", then 4071 with this option set a lookup of 4072 "FTP" will return "FTP.Foo.ORG"; if 4073 clear it returns "Cruft.FOO.ORG". N.B. 4074 you may not see any effect until your 4075 downstream neighbors stop doing CNAME 4076 lookups as well. 4077confFROM_LINE UnixFromLine [From $g $d] The From_ line used 4078 when sending to files or programs. 4079confSINGLE_LINE_FROM_HEADER SingleLineFromHeader 4080 [False] From: lines that have 4081 embedded newlines are unwrapped 4082 onto one line. 4083confALLOW_BOGUS_HELO AllowBogusHELO [False] Allow HELO SMTP command that 4084 does not include a host name. 4085confMUST_QUOTE_CHARS MustQuoteChars [.'] Characters to be quoted in a full 4086 name phrase (@,;:\()[] are automatic). 4087confOPERATORS OperatorChars [.:%@!^/[]+] Address operator 4088 characters. 4089confSMTP_LOGIN_MSG SmtpGreetingMessage 4090 [$j Sendmail $v/$Z; $b] 4091 The initial (spontaneous) SMTP 4092 greeting message. The word "ESMTP" 4093 will be inserted between the first and 4094 second words to convince other 4095 sendmails to try to speak ESMTP. 4096confDONT_INIT_GROUPS DontInitGroups [False] If set, the initgroups(3) 4097 routine will never be invoked. You 4098 might want to do this if you are 4099 running NIS and you have a large group 4100 map, since this call does a sequential 4101 scan of the map; in a large site this 4102 can cause your ypserv to run 4103 essentially full time. If you set 4104 this, agents run on behalf of users 4105 will only have their primary 4106 (/etc/passwd) group permissions. 4107confUNSAFE_GROUP_WRITES UnsafeGroupWrites 4108 [True] If set, group-writable 4109 :include: and .forward files are 4110 considered "unsafe", that is, programs 4111 and files cannot be directly referenced 4112 from such files. World-writable files 4113 are always considered unsafe. 4114 Notice: this option is deprecated and 4115 will be removed in future versions; 4116 Set GroupWritableForwardFileSafe 4117 and GroupWritableIncludeFileSafe in 4118 DontBlameSendmail if required. 4119confCONNECT_ONLY_TO ConnectOnlyTo [undefined] override connection 4120 address (for testing). 4121confCONTROL_SOCKET_NAME ControlSocketName 4122 [undefined] Control socket for daemon 4123 management. 4124confDOUBLE_BOUNCE_ADDRESS DoubleBounceAddress 4125 [postmaster] If an error occurs when 4126 sending an error message, send that 4127 "double bounce" error message to this 4128 address. If it expands to an empty 4129 string, double bounces are dropped. 4130confSOFT_BOUNCE SoftBounce [False] If set, issue temporary errors 4131 (4xy) instead of permanent errors 4132 (5xy). This can be useful during 4133 testing of a new configuration to 4134 avoid erroneous bouncing of mails. 4135confDEAD_LETTER_DROP DeadLetterDrop [undefined] Filename to save bounce 4136 messages which could not be returned 4137 to the user or sent to postmaster. 4138 If not set, the queue file will 4139 be renamed. 4140confRRT_IMPLIES_DSN RrtImpliesDsn [False] Return-Receipt-To: header 4141 implies DSN request. 4142confRUN_AS_USER RunAsUser [undefined] If set, become this user 4143 when reading and delivering mail. 4144 Causes all file reads (e.g., .forward 4145 and :include: files) to be done as 4146 this user. Also, all programs will 4147 be run as this user, and all output 4148 files will be written as this user. 4149confMAX_RCPTS_PER_MESSAGE MaxRecipientsPerMessage 4150 [infinite] If set, allow no more than 4151 the specified number of recipients in 4152 an SMTP envelope. Further recipients 4153 receive a 452 error code (i.e., they 4154 are deferred for the next delivery 4155 attempt). 4156confBAD_RCPT_THROTTLE BadRcptThrottle [infinite] If set and the specified 4157 number of recipients in a single SMTP 4158 transaction have been rejected, sleep 4159 for one second after each subsequent 4160 RCPT command in that transaction. 4161confDONT_PROBE_INTERFACES DontProbeInterfaces 4162 [False] If set, sendmail will _not_ 4163 insert the names and addresses of any 4164 local interfaces into class {w} 4165 (list of known "equivalent" addresses). 4166 If you set this, you must also include 4167 some support for these addresses (e.g., 4168 in a mailertable entry) -- otherwise, 4169 mail to addresses in this list will 4170 bounce with a configuration error. 4171 If set to "loopback" (without 4172 quotes), sendmail will skip 4173 loopback interfaces (e.g., "lo0"). 4174confPID_FILE PidFile [system dependent] Location of pid 4175 file. 4176confPROCESS_TITLE_PREFIX ProcessTitlePrefix 4177 [undefined] Prefix string for the 4178 process title shown on 'ps' listings. 4179confDONT_BLAME_SENDMAIL DontBlameSendmail 4180 [safe] Override sendmail's file 4181 safety checks. This will definitely 4182 compromise system security and should 4183 not be used unless absolutely 4184 necessary. 4185confREJECT_MSG - [550 Access denied] The message 4186 given if the access database contains 4187 REJECT in the value portion. 4188confRELAY_MSG - [550 Relaying denied] The message 4189 given if an unauthorized relaying 4190 attempt is rejected. 4191confDF_BUFFER_SIZE DataFileBufferSize 4192 [4096] The maximum size of a 4193 memory-buffered data (df) file 4194 before a disk-based file is used. 4195confXF_BUFFER_SIZE XScriptFileBufferSize 4196 [4096] The maximum size of a 4197 memory-buffered transcript (xf) 4198 file before a disk-based file is 4199 used. 4200confAUTH_MECHANISMS AuthMechanisms [GSSAPI KERBEROS_V4 DIGEST-MD5 4201 CRAM-MD5] List of authentication 4202 mechanisms for AUTH (separated by 4203 spaces). The advertised list of 4204 authentication mechanisms will be the 4205 intersection of this list and the list 4206 of available mechanisms as determined 4207 by the Cyrus SASL library. 4208confAUTH_REALM AuthRealm [undefined] The authentication realm 4209 that is passed to the Cyrus SASL 4210 library. If no realm is specified, 4211 $j is used. 4212confDEF_AUTH_INFO DefaultAuthInfo [undefined] Name of file that contains 4213 authentication information for 4214 outgoing connections. This file must 4215 contain the user id, the authorization 4216 id, the password (plain text), the 4217 realm to use, and the list of 4218 mechanisms to try, each on a separate 4219 line and must be readable by root (or 4220 the trusted user) only. If no realm 4221 is specified, $j is used. If no 4222 mechanisms are given in the file, 4223 AuthMechanisms is used. Notice: this 4224 option is deprecated and will be 4225 removed in future versions; it doesn't 4226 work for the MSP since it can't read 4227 the file. Use the authinfo ruleset 4228 instead. See also the section SMTP 4229 AUTHENTICATION. 4230confAUTH_OPTIONS AuthOptions [undefined] If this option is 'A' 4231 then the AUTH= parameter for the 4232 MAIL FROM command is only issued 4233 when authentication succeeded. 4234 See doc/op/op.me for more options 4235 and details. 4236confAUTH_MAX_BITS AuthMaxBits [INT_MAX] Limit the maximum encryption 4237 strength for the security layer in 4238 SMTP AUTH (SASL). Default is 4239 essentially unlimited. 4240confTLS_SRV_OPTIONS TLSSrvOptions If this option is 'V' no client 4241 verification is performed, i.e., 4242 the server doesn't ask for a 4243 certificate. 4244confLDAP_DEFAULT_SPEC LDAPDefaultSpec [undefined] Default map 4245 specification for LDAP maps. The 4246 value should only contain LDAP 4247 specific settings such as "-h host 4248 -p port -d bindDN", etc. The 4249 settings will be used for all LDAP 4250 maps unless they are specified in 4251 the individual map specification 4252 ('K' command). 4253confCACERT_PATH CACertPath [undefined] Path to directory 4254 with certs of CAs. 4255confCACERT CACertFile [undefined] File containing one CA 4256 cert. 4257confSERVER_CERT ServerCertFile [undefined] File containing the 4258 cert of the server, i.e., this cert 4259 is used when sendmail acts as 4260 server. 4261confSERVER_KEY ServerKeyFile [undefined] File containing the 4262 private key belonging to the server 4263 cert. 4264confCLIENT_CERT ClientCertFile [undefined] File containing the 4265 cert of the client, i.e., this cert 4266 is used when sendmail acts as 4267 client. 4268confCLIENT_KEY ClientKeyFile [undefined] File containing the 4269 private key belonging to the client 4270 cert. 4271confCRL CRLFile [undefined] File containing certificate 4272 revocation status, useful for X.509v3 4273 authentication. Note that CRL requires 4274 at least OpenSSL version 0.9.7. 4275confDH_PARAMETERS DHParameters [undefined] File containing the 4276 DH parameters. 4277confRAND_FILE RandFile [undefined] File containing random 4278 data (use prefix file:) or the 4279 name of the UNIX socket if EGD is 4280 used (use prefix egd:). STARTTLS 4281 requires this option if the compile 4282 flag HASURANDOM is not set (see 4283 sendmail/README). 4284confNICE_QUEUE_RUN NiceQueueRun [undefined] If set, the priority of 4285 queue runners is set the given value 4286 (nice(3)). 4287confDIRECT_SUBMISSION_MODIFIERS DirectSubmissionModifiers 4288 [undefined] Defines {daemon_flags} 4289 for direct submissions. 4290confUSE_MSP UseMSP [undefined] Use as mail submission 4291 program, see sendmail/SECURITY. 4292confDELIVER_BY_MIN DeliverByMin [0] Minimum time for Deliver By 4293 SMTP Service Extension (RFC 2852). 4294confREQUIRES_DIR_FSYNC RequiresDirfsync [true] RequiresDirfsync can 4295 be used to turn off the compile time 4296 flag REQUIRES_DIR_FSYNC at runtime. 4297 See sendmail/README for details. 4298confSHARED_MEMORY_KEY SharedMemoryKey [0] Key for shared memory. 4299confSHARED_MEMORY_KEY_FILE 4300 SharedMemoryKeyFile 4301 [undefined] File where the 4302 automatically selected key for 4303 shared memory is stored. 4304confFAST_SPLIT FastSplit [1] If set to a value greater than 4305 zero, the initial MX lookups on 4306 addresses is suppressed when they 4307 are sorted which may result in 4308 faster envelope splitting. If the 4309 mail is submitted directly from the 4310 command line, then the value also 4311 limits the number of processes to 4312 deliver the envelopes. 4313confMAILBOX_DATABASE MailboxDatabase [pw] Type of lookup to find 4314 information about local mailboxes. 4315confDEQUOTE_OPTS - [empty] Additional options for the 4316 dequote map. 4317confMAX_NOOP_COMMANDS MaxNOOPCommands [20] Maximum number of "useless" 4318 commands before the SMTP server 4319 will slow down responding. 4320confHELO_NAME HeloName If defined, use as name for EHLO/HELO 4321 command (instead of $j). 4322confINPUT_MAIL_FILTERS InputMailFilters 4323 A comma separated list of filters 4324 which determines which filters and 4325 the invocation sequence are 4326 contacted for incoming SMTP 4327 messages. If none are set, no 4328 filters will be contacted. 4329confMILTER_LOG_LEVEL Milter.LogLevel [9] Log level for input mail filter 4330 actions, defaults to LogLevel. 4331confMILTER_MACROS_CONNECT Milter.macros.connect 4332 [j, _, {daemon_name}, {if_name}, 4333 {if_addr}] Macros to transmit to 4334 milters when a session connection 4335 starts. 4336confMILTER_MACROS_HELO Milter.macros.helo 4337 [{tls_version}, {cipher}, 4338 {cipher_bits}, {cert_subject}, 4339 {cert_issuer}] Macros to transmit to 4340 milters after HELO/EHLO command. 4341confMILTER_MACROS_ENVFROM Milter.macros.envfrom 4342 [i, {auth_type}, {auth_authen}, 4343 {auth_ssf}, {auth_author}, 4344 {mail_mailer}, {mail_host}, 4345 {mail_addr}] Macros to transmit to 4346 milters after MAIL FROM command. 4347confMILTER_MACROS_ENVRCPT Milter.macros.envrcpt 4348 [{rcpt_mailer}, {rcpt_host}, 4349 {rcpt_addr}] Macros to transmit to 4350 milters after RCPT TO command. 4351confMILTER_MACROS_EOM Milter.macros.eom 4352 [{msg_id}] Macros to transmit to 4353 milters after the terminating 4354 DATA '.' is received. 4355confMILTER_MACROS_EOH Milter.macros.eoh 4356 Macros to transmit to milters 4357 after the end of headers. 4358confMILTER_MACROS_DATA Milter.macros.data 4359 Macros to transmit to milters 4360 after DATA command is received. 4361 4362 4363See also the description of OSTYPE for some parameters that can be 4364tweaked (generally pathnames to mailers). 4365 4366ClientPortOptions and DaemonPortOptions are special cases since multiple 4367clients/daemons can be defined. This can be done via 4368 4369 CLIENT_OPTIONS(`field1=value1,field2=value2,...') 4370 DAEMON_OPTIONS(`field1=value1,field2=value2,...') 4371 4372Note that multiple CLIENT_OPTIONS() commands (and therefore multiple 4373ClientPortOptions settings) are allowed in order to give settings for each 4374protocol family (e.g., one for Family=inet and one for Family=inet6). A 4375restriction placed on one family only affects outgoing connections on that 4376particular family. 4377 4378If DAEMON_OPTIONS is not used, then the default is 4379 4380 DAEMON_OPTIONS(`Port=smtp, Name=MTA') 4381 DAEMON_OPTIONS(`Port=587, Name=MSA, M=E') 4382 4383If you use one DAEMON_OPTIONS macro, it will alter the parameters 4384of the first of these. The second will still be defaulted; it 4385represents a "Message Submission Agent" (MSA) as defined by RFC 43862476 (see below). To turn off the default definition for the MSA, 4387use FEATURE(`no_default_msa') (see also FEATURES). If you use 4388additional DAEMON_OPTIONS macros, they will add additional daemons. 4389 4390Example 1: To change the port for the SMTP listener, while 4391still using the MSA default, use 4392 DAEMON_OPTIONS(`Port=925, Name=MTA') 4393 4394Example 2: To change the port for the MSA daemon, while still 4395using the default SMTP port, use 4396 FEATURE(`no_default_msa') 4397 DAEMON_OPTIONS(`Name=MTA') 4398 DAEMON_OPTIONS(`Port=987, Name=MSA, M=E') 4399 4400Note that if the first of those DAEMON_OPTIONS lines were omitted, then 4401there would be no listener on the standard SMTP port. 4402 4403Example 3: To listen on both IPv4 and IPv6 interfaces, use 4404 4405 DAEMON_OPTIONS(`Name=MTA-v4, Family=inet') 4406 DAEMON_OPTIONS(`Name=MTA-v6, Family=inet6') 4407 4408A "Message Submission Agent" still uses all of the same rulesets for 4409processing the message (and therefore still allows message rejection via 4410the check_* rulesets). In accordance with the RFC, the MSA will ensure 4411that all domains in envelope addresses are fully qualified if the message 4412is relayed to another MTA. It will also enforce the normal address syntax 4413rules and log error messages. Additionally, by using the M=a modifier you 4414can require authentication before messages are accepted by the MSA. 4415Notice: Do NOT use the 'a' modifier on a public accessible MTA! Finally, 4416the M=E modifier shown above disables ETRN as required by RFC 2476. 4417 4418Mail filters can be defined using the INPUT_MAIL_FILTER() and MAIL_FILTER() 4419commands: 4420 4421 INPUT_MAIL_FILTER(`sample', `S=local:/var/run/f1.sock') 4422 MAIL_FILTER(`myfilter', `S=inet:3333@localhost') 4423 4424The INPUT_MAIL_FILTER() command causes the filter(s) to be called in the 4425same order they were specified by also setting confINPUT_MAIL_FILTERS. A 4426filter can be defined without adding it to the input filter list by using 4427MAIL_FILTER() instead of INPUT_MAIL_FILTER() in your .mc file. 4428Alternatively, you can reset the list of filters and their order by setting 4429confINPUT_MAIL_FILTERS option after all INPUT_MAIL_FILTER() commands in 4430your .mc file. 4431 4432 4433+----------------------------+ 4434| MESSAGE SUBMISSION PROGRAM | 4435+----------------------------+ 4436 4437The purpose of the message submission program (MSP) is explained 4438in sendmail/SECURITY. This section contains a list of caveats and 4439a few hints how for those who want to tweak the default configuration 4440for it (which is installed as submit.cf). 4441 4442Notice: do not add options/features to submit.mc unless you are 4443absolutely sure you need them. Options you may want to change 4444include: 4445 4446- confTRUSTED_USERS, FEATURE(`use_ct_file'), and confCT_FILE for 4447 avoiding X-Authentication warnings. 4448- confTIME_ZONE to change it from the default `USE_TZ'. 4449- confDELIVERY_MODE is set to interactive in msp.m4 instead 4450 of the default background mode. 4451- FEATURE(stickyhost) and LOCAL_RELAY to send unqualified addresses 4452 to the LOCAL_RELAY instead of the default relay. 4453- confRAND_FILE if you use STARTTLS and sendmail is not compiled with 4454 the flag HASURANDOM. 4455 4456The MSP performs hostname canonicalization by default. As also 4457explained in sendmail/SECURITY, mail may end up for various DNS 4458related reasons in the MSP queue. This problem can be minimized by 4459using 4460 4461 FEATURE(`nocanonify', `canonify_hosts') 4462 define(`confDIRECT_SUBMISSION_MODIFIERS', `C') 4463 4464See the discussion about nocanonify for possible side effects. 4465 4466Some things are not intended to work with the MSP. These include 4467features that influence the delivery process (e.g., mailertable, 4468aliases), or those that are only important for a SMTP server (e.g., 4469virtusertable, DaemonPortOptions, multiple queues). Moreover, 4470relaxing certain restrictions (RestrictQueueRun, permissions on 4471queue directory) or adding features (e.g., enabling prog/file mailer) 4472can cause security problems. 4473 4474Other things don't work well with the MSP and require tweaking or 4475workarounds. For example, to allow for client authentication it 4476is not just sufficient to provide a client certificate and the 4477corresponding key, but it is also necessary to make the key group 4478(smmsp) readable and tell sendmail not to complain about that, i.e., 4479 4480 define(`confDONT_BLAME_SENDMAIL', `GroupReadableKeyFile') 4481 4482If the MSP should actually use AUTH then the necessary data 4483should be placed in a map as explained in SMTP AUTHENTICATION: 4484 4485FEATURE(`authinfo', `DATABASE_MAP_TYPE /etc/mail/msp-authinfo') 4486 4487/etc/mail/msp-authinfo should contain an entry like: 4488 4489 AuthInfo:127.0.0.1 "U:smmsp" "P:secret" "M:DIGEST-MD5" 4490 4491The file and the map created by makemap should be owned by smmsp, 4492its group should be smmsp, and it should have mode 640. The database 4493used by the MTA for AUTH must have a corresponding entry. 4494Additionally the MTA must trust this authentication data so the AUTH= 4495part will be relayed on to the next hop. This can be achieved by 4496adding the following to your sendmail.mc file: 4497 4498 LOCAL_RULESETS 4499 SLocal_trust_auth 4500 R$* $: $&{auth_authen} 4501 Rsmmsp $# OK 4502 4503Note: the authentication data can leak to local users who invoke 4504the MSP with debug options or even with -v. For that reason either 4505an authentication mechanism that does not show the password in the 4506AUTH dialogue (e.g., DIGEST-MD5) or a different authentication 4507method like STARTTLS should be used. 4508 4509feature/msp.m4 defines almost all settings for the MSP. Most of 4510those should not be changed at all. Some of the features and options 4511can be overridden if really necessary. It is a bit tricky to do 4512this, because it depends on the actual way the option is defined 4513in feature/msp.m4. If it is directly defined (i.e., define()) then 4514the modified value must be defined after 4515 4516 FEATURE(`msp') 4517 4518If it is conditionally defined (i.e., ifdef()) then the desired 4519value must be defined before the FEATURE line in the .mc file. 4520To see how the options are defined read feature/msp.m4. 4521 4522 4523+--------------------------+ 4524| FORMAT OF FILES AND MAPS | 4525+--------------------------+ 4526 4527Files that define classes, i.e., F{classname}, consist of lines 4528each of which contains a single element of the class. For example, 4529/etc/mail/local-host-names may have the following content: 4530 4531my.domain 4532another.domain 4533 4534Maps must be created using makemap(8) , e.g., 4535 4536 makemap hash MAP < MAP 4537 4538In general, a text file from which a map is created contains lines 4539of the form 4540 4541key value 4542 4543where 'key' and 'value' are also called LHS and RHS, respectively. 4544By default, the delimiter between LHS and RHS is a non-empty sequence 4545of white space characters. 4546 4547 4548+------------------+ 4549| DIRECTORY LAYOUT | 4550+------------------+ 4551 4552Within this directory are several subdirectories, to wit: 4553 4554m4 General support routines. These are typically 4555 very important and should not be changed without 4556 very careful consideration. 4557 4558cf The configuration files themselves. They have 4559 ".mc" suffixes, and must be run through m4 to 4560 become complete. The resulting output should 4561 have a ".cf" suffix. 4562 4563ostype Definitions describing a particular operating 4564 system type. These should always be referenced 4565 using the OSTYPE macro in the .mc file. Examples 4566 include "bsd4.3", "bsd4.4", "sunos3.5", and 4567 "sunos4.1". 4568 4569domain Definitions describing a particular domain, referenced 4570 using the DOMAIN macro in the .mc file. These are 4571 site dependent; for example, "CS.Berkeley.EDU.m4" 4572 describes hosts in the CS.Berkeley.EDU subdomain. 4573 4574mailer Descriptions of mailers. These are referenced using 4575 the MAILER macro in the .mc file. 4576 4577sh Shell files used when building the .cf file from the 4578 .mc file in the cf subdirectory. 4579 4580feature These hold special orthogonal features that you might 4581 want to include. They should be referenced using 4582 the FEATURE macro. 4583 4584hack Local hacks. These can be referenced using the HACK 4585 macro. They shouldn't be of more than voyeuristic 4586 interest outside the .Berkeley.EDU domain, but who knows? 4587 4588siteconfig Site configuration -- e.g., tables of locally connected 4589 UUCP sites. 4590 4591 4592+------------------------+ 4593| ADMINISTRATIVE DETAILS | 4594+------------------------+ 4595 4596The following sections detail usage of certain internal parts of the 4597sendmail.cf file. Read them carefully if you are trying to modify 4598the current model. If you find the above descriptions adequate, these 4599should be {boring, confusing, tedious, ridiculous} (pick one or more). 4600 4601RULESETS (* means built in to sendmail) 4602 4603 0 * Parsing 4604 1 * Sender rewriting 4605 2 * Recipient rewriting 4606 3 * Canonicalization 4607 4 * Post cleanup 4608 5 * Local address rewrite (after aliasing) 4609 1x mailer rules (sender qualification) 4610 2x mailer rules (recipient qualification) 4611 3x mailer rules (sender header qualification) 4612 4x mailer rules (recipient header qualification) 4613 5x mailer subroutines (general) 4614 6x mailer subroutines (general) 4615 7x mailer subroutines (general) 4616 8x reserved 4617 90 Mailertable host stripping 4618 96 Bottom half of Ruleset 3 (ruleset 6 in old sendmail) 4619 97 Hook for recursive ruleset 0 call (ruleset 7 in old sendmail) 4620 98 Local part of ruleset 0 (ruleset 8 in old sendmail) 4621 4622 4623MAILERS 4624 4625 0 local, prog local and program mailers 4626 1 [e]smtp, relay SMTP channel 4627 2 uucp-* UNIX-to-UNIX Copy Program 4628 3 netnews Network News delivery 4629 4 fax Sam Leffler's HylaFAX software 4630 5 mail11 DECnet mailer 4631 4632 4633MACROS 4634 4635 A 4636 B Bitnet Relay 4637 C DECnet Relay 4638 D The local domain -- usually not needed 4639 E reserved for X.400 Relay 4640 F FAX Relay 4641 G 4642 H mail Hub (for mail clusters) 4643 I 4644 J 4645 K 4646 L Luser Relay 4647 M Masquerade (who you claim to be) 4648 N 4649 O 4650 P 4651 Q 4652 R Relay (for unqualified names) 4653 S Smart Host 4654 T 4655 U my UUCP name (if you have a UUCP connection) 4656 V UUCP Relay (class {V} hosts) 4657 W UUCP Relay (class {W} hosts) 4658 X UUCP Relay (class {X} hosts) 4659 Y UUCP Relay (all other hosts) 4660 Z Version number 4661 4662 4663CLASSES 4664 4665 A 4666 B domains that are candidates for bestmx lookup 4667 C 4668 D 4669 E addresses that should not seem to come from $M 4670 F hosts this system forward for 4671 G domains that should be looked up in genericstable 4672 H 4673 I 4674 J 4675 K 4676 L addresses that should not be forwarded to $R 4677 M domains that should be mapped to $M 4678 N host/domains that should not be mapped to $M 4679 O operators that indicate network operations (cannot be in local names) 4680 P top level pseudo-domains: BITNET, DECNET, FAX, UUCP, etc. 4681 Q 4682 R domains this system is willing to relay (pass anti-spam filters) 4683 S 4684 T 4685 U locally connected UUCP hosts 4686 V UUCP hosts connected to relay $V 4687 W UUCP hosts connected to relay $W 4688 X UUCP hosts connected to relay $X 4689 Y locally connected smart UUCP hosts 4690 Z locally connected domain-ized UUCP hosts 4691 . the class containing only a dot 4692 [ the class containing only a left bracket 4693 4694 4695M4 DIVERSIONS 4696 4697 1 Local host detection and resolution 4698 2 Local Ruleset 3 additions 4699 3 Local Ruleset 0 additions 4700 4 UUCP Ruleset 0 additions 4701 5 locally interpreted names (overrides $R) 4702 6 local configuration (at top of file) 4703 7 mailer definitions 4704 8 DNS based blacklists 4705 9 special local rulesets (1 and 2) 4706 4707$Revision: 8.730 $, Last updated $Date: 2014/01/16 15:55:51 $ 4708