1# ACCESS(5) ACCESS(5) 2# 3# NAME 4# access - Postfix SMTP server access table 5# 6# SYNOPSIS 7# postmap /etc/postfix/access 8# 9# postmap -q "string" /etc/postfix/access 10# 11# postmap -q - /etc/postfix/access <inputfile 12# 13# DESCRIPTION 14# This document describes access control on remote SMTP 15# client information: host names, network addresses, and 16# envelope sender or recipient addresses; it is implemented 17# by the Postfix SMTP server. See header_checks(5) or 18# body_checks(5) for access control on the content of email 19# messages. 20# 21# Normally, the access(5) table is specified as a text file 22# that serves as input to the postmap(1) command. The 23# result, an indexed file in dbm or db format, is used for 24# fast searching by the mail system. Execute the command 25# "postmap /etc/postfix/access" to rebuild an indexed file 26# after changing the corresponding text file. 27# 28# When the table is provided via other means such as NIS, 29# LDAP or SQL, the same lookups are done as for ordinary 30# indexed files. 31# 32# Alternatively, the table can be provided as a regular- 33# expression map where patterns are given as regular expres- 34# sions, or lookups can be directed to TCP-based server. In 35# those cases, the lookups are done in a slightly different 36# way as described below under "REGULAR EXPRESSION TABLES" 37# or "TCP-BASED TABLES". 38# 39# CASE FOLDING 40# The search string is folded to lowercase before database 41# lookup. As of Postfix 2.3, the search string is not case 42# folded with database types such as regexp: or pcre: whose 43# lookup fields can match both upper and lower case. 44# 45# TABLE FORMAT 46# The input format for the postmap(1) command is as follows: 47# 48# pattern action 49# When pattern matches a mail address, domain or host 50# address, perform the corresponding action. 51# 52# blank lines and comments 53# Empty lines and whitespace-only lines are ignored, 54# as are lines whose first non-whitespace character 55# is a `#'. 56# 57# multi-line text 58# A logical line starts with non-whitespace text. A 59# line that starts with whitespace continues a logi- 60# cal line. 61# 62# EMAIL ADDRESS PATTERNS 63# With lookups from indexed files such as DB or DBM, or from 64# networked tables such as NIS, LDAP or SQL, patterns are 65# tried in the order as listed below: 66# 67# user@domain 68# Matches the specified mail address. 69# 70# domain.tld 71# Matches domain.tld as the domain part of an email 72# address. 73# 74# The pattern domain.tld also matches subdomains, but 75# only when the string smtpd_access_maps is listed in 76# the Postfix parent_domain_matches_subdomains con- 77# figuration setting. 78# 79# .domain.tld 80# Matches subdomains of domain.tld, but only when the 81# string smtpd_access_maps is not listed in the Post- 82# fix parent_domain_matches_subdomains configuration 83# setting. 84# 85# user@ Matches all mail addresses with the specified user 86# part. 87# 88# Note: lookup of the null sender address is not possible 89# with some types of lookup table. By default, Postfix uses 90# <> as the lookup key for such addresses. The value is 91# specified with the smtpd_null_access_lookup_key parameter 92# in the Postfix main.cf file. 93# 94# EMAIL ADDRESS EXTENSION 95# When a mail address localpart contains the optional recip- 96# ient delimiter (e.g., user+foo@domain), the lookup order 97# becomes: user+foo@domain, user@domain, domain, user+foo@, 98# and user@. 99# 100# HOST NAME/ADDRESS PATTERNS 101# With lookups from indexed files such as DB or DBM, or from 102# networked tables such as NIS, LDAP or SQL, the following 103# lookup patterns are examined in the order as listed: 104# 105# domain.tld 106# Matches domain.tld. 107# 108# The pattern domain.tld also matches subdomains, but 109# only when the string smtpd_access_maps is listed in 110# the Postfix parent_domain_matches_subdomains con- 111# figuration setting. 112# 113# .domain.tld 114# Matches subdomains of domain.tld, but only when the 115# string smtpd_access_maps is not listed in the Post- 116# fix parent_domain_matches_subdomains configuration 117# setting. 118# 119# net.work.addr.ess 120# 121# net.work.addr 122# 123# net.work 124# 125# net Matches the specified IPv4 host address or subnet- 126# work. An IPv4 host address is a sequence of four 127# decimal octets separated by ".". 128# 129# Subnetworks are matched by repeatedly truncating 130# the last ".octet" from the remote IPv4 host address 131# string until a match is found in the access table, 132# or until further truncation is not possible. 133# 134# NOTE 1: The access map lookup key must be in canon- 135# ical form: do not specify unnecessary null charac- 136# ters, and do not enclose network address informa- 137# tion with "[]" characters. 138# 139# NOTE 2: use the cidr lookup table type to specify 140# network/netmask patterns. See cidr_table(5) for 141# details. 142# 143# net:work:addr:ess 144# 145# net:work:addr 146# 147# net:work 148# 149# net Matches the specified IPv6 host address or subnet- 150# work. An IPv6 host address is a sequence of three 151# to eight hexadecimal octet pairs separated by ":". 152# 153# Subnetworks are matched by repeatedly truncating 154# the last ":octetpair" from the remote IPv6 host 155# address string until a match is found in the access 156# table, or until further truncation is not possible. 157# 158# NOTE 1: the truncation and comparison are done with 159# the string representation of the IPv6 host address. 160# Thus, not all the ":" subnetworks will be tried. 161# 162# NOTE 2: The access map lookup key must be in canon- 163# ical form: do not specify unnecessary null charac- 164# ters, and do not enclose network address informa- 165# tion with "[]" characters. 166# 167# NOTE 3: use the cidr lookup table type to specify 168# network/netmask patterns. See cidr_table(5) for 169# details. 170# 171# IPv6 support is available in Postfix 2.2 and later. 172# 173# ACCEPT ACTIONS 174# OK Accept the address etc. that matches the pattern. 175# 176# all-numerical 177# An all-numerical result is treated as OK. This for- 178# mat is generated by address-based relay authoriza- 179# tion schemes such as pop-before-smtp. 180# 181# REJECT ACTIONS 182# Postfix version 2.3 and later support enhanced status 183# codes as defined in RFC 3463. When no code is specified 184# at the beginning of the text below, Postfix inserts a 185# default enhanced status code of "5.7.1" in the case of 186# reject actions, and "4.7.1" in the case of defer actions. 187# See "ENHANCED STATUS CODES" below. 188# 189# 4NN text 190# 191# 5NN text 192# Reject the address etc. that matches the pattern, 193# and respond with the numerical three-digit code and 194# text. 4NN means "try again later", while 5NN means 195# "do not try again". 196# 197# The following responses have special meaning for 198# the Postfix SMTP server: 199# 200# 421 text (Postfix 2.3 and later) 201# 202# 521 text (Postfix 2.6 and later) 203# After responding with the numerical three- 204# digit code and text, disconnect immediately 205# from the SMTP client. This frees up SMTP 206# server resources so that they can be made 207# available to another SMTP client. 208# 209# Note: The "521" response should be used only 210# with botnets and other malware where inter- 211# operability is of no concern. The "send 521 212# and disconnect" behavior is NOT defined in 213# the SMTP standard. 214# 215# REJECT optional text... 216# Reject the address etc. that matches the pattern. 217# Reply with "$access_map_reject_code optional 218# text..." when the optional text is specified, oth- 219# erwise reply with a generic error response message. 220# 221# DEFER optional text... 222# Reject the address etc. that matches the pattern. 223# Reply with "$access_map_defer_code optional 224# text..." when the optional text is specified, oth- 225# erwise reply with a generic error response message. 226# 227# This feature is available in Postfix 2.6 and later. 228# 229# DEFER_IF_REJECT optional text... 230# Defer the request if some later restriction would 231# result in a REJECT action. Reply with 232# "$access_map_defer_code 4.7.1 optional text..." 233# when the optional text is specified, otherwise 234# reply with a generic error response message. 235# 236# Prior to Postfix 2.6, the SMTP reply code is 450. 237# 238# This feature is available in Postfix 2.1 and later. 239# 240# DEFER_IF_PERMIT optional text... 241# Defer the request if some later restriction would 242# result in a an explicit or implicit PERMIT action. 243# Reply with "$access_map_defer_code 4.7.1 optional 244# text..." when the optional text is specified, oth- 245# erwise reply with a generic error response message. 246# 247# Prior to Postfix 2.6, the SMTP reply code is 450. 248# 249# This feature is available in Postfix 2.1 and later. 250# 251# OTHER ACTIONS 252# restriction... 253# Apply the named UCE restriction(s) (permit, reject, 254# reject_unauth_destination, and so on). 255# 256# BCC user@domain 257# Send one copy of the message to the specified 258# recipient. 259# 260# If multiple BCC actions are specified within the 261# same SMTP MAIL transaction, only the last action 262# will be used. 263# 264# This feature is not part of the stable Postfix 265# release. 266# 267# DISCARD optional text... 268# Claim successful delivery and silently discard the 269# message. Log the optional text if specified, oth- 270# erwise log a generic message. 271# 272# Note: this action currently affects all recipients 273# of the message. To discard only one recipient 274# without discarding the entire message, use the 275# transport(5) table to direct mail to the discard(8) 276# service. 277# 278# This feature is available in Postfix 2.0 and later. 279# 280# DUNNO Pretend that the lookup key was not found. This 281# prevents Postfix from trying substrings of the 282# lookup key (such as a subdomain name, or a network 283# address subnetwork). 284# 285# This feature is available in Postfix 2.0 and later. 286# 287# FILTER transport:destination 288# After the message is queued, send the entire mes- 289# sage through the specified external content filter. 290# The transport name specifies the first field of a 291# mail delivery agent definition in master.cf; the 292# syntax of the next-hop destination is described in 293# the manual page of the corresponding delivery 294# agent. More information about external content 295# filters is in the Postfix FILTER_README file. 296# 297# Note 1: do not use $number regular expression sub- 298# stitutions for transport or destination unless you 299# know that the information has a trusted origin. 300# 301# Note 2: this action overrides the main.cf con- 302# tent_filter setting, and affects all recipients of 303# the message. In the case that multiple FILTER 304# actions fire, only the last one is executed. 305# 306# Note 3: the purpose of the FILTER command is to 307# override message routing. To override the recipi- 308# ent's transport but not the next-hop destination, 309# specify an empty filter destination (Postfix 2.7 310# and later), or specify a transport:destination that 311# delivers through a different Postfix instance 312# (Postfix 2.6 and earlier). Other options are using 313# the recipient-dependent transport_maps or the sen- 314# der-dependent sender_dependent_default_transport- 315# _maps features. 316# 317# This feature is available in Postfix 2.0 and later. 318# 319# HOLD optional text... 320# Place the message on the hold queue, where it will 321# sit until someone either deletes it or releases it 322# for delivery. Log the optional text if specified, 323# otherwise log a generic message. 324# 325# Mail that is placed on hold can be examined with 326# the postcat(1) command, and can be destroyed or 327# released with the postsuper(1) command. 328# 329# Note: use "postsuper -r" to release mail that was 330# kept on hold for a significant fraction of $maxi- 331# mal_queue_lifetime or $bounce_queue_lifetime, or 332# longer. Use "postsuper -H" only for mail that will 333# not expire within a few delivery attempts. 334# 335# Note: this action currently affects all recipients 336# of the message. 337# 338# This feature is available in Postfix 2.0 and later. 339# 340# PREPEND headername: headervalue 341# Prepend the specified message header to the mes- 342# sage. When more than one PREPEND action executes, 343# the first prepended header appears before the sec- 344# ond etc. prepended header. 345# 346# Note: this action must execute before the message 347# content is received; it cannot execute in the con- 348# text of smtpd_end_of_data_restrictions. 349# 350# This feature is available in Postfix 2.1 and later. 351# 352# REDIRECT user@domain 353# After the message is queued, send the message to 354# the specified address instead of the intended 355# recipient(s). 356# 357# Note: this action overrides the FILTER action, and 358# currently affects all recipients of the message. 359# 360# This feature is available in Postfix 2.1 and later. 361# 362# WARN optional text... 363# Log a warning with the optional text, together with 364# client information and if available, with helo, 365# sender, recipient and protocol information. 366# 367# This feature is available in Postfix 2.1 and later. 368# 369# ENHANCED STATUS CODES 370# Postfix version 2.3 and later support enhanced status 371# codes as defined in RFC 3463. When an enhanced status 372# code is specified in an access table, it is subject to 373# modification. The following transformations are needed 374# when the same access table is used for client, helo, 375# sender, or recipient access restrictions; they happen 376# regardless of whether Postfix replies to a MAIL FROM, RCPT 377# TO or other SMTP command. 378# 379# o When a sender address matches a REJECT action, the 380# Postfix SMTP server will transform a recipient DSN 381# status (e.g., 4.1.1-4.1.6) into the corresponding 382# sender DSN status, and vice versa. 383# 384# o When non-address information matches a REJECT 385# action (such as the HELO command argument or the 386# client hostname/address), the Postfix SMTP server 387# will transform a sender or recipient DSN status 388# into a generic non-address DSN status (e.g., 389# 4.0.0). 390# 391# REGULAR EXPRESSION TABLES 392# This section describes how the table lookups change when 393# the table is given in the form of regular expressions. For 394# a description of regular expression lookup table syntax, 395# see regexp_table(5) or pcre_table(5). 396# 397# Each pattern is a regular expression that is applied to 398# the entire string being looked up. Depending on the appli- 399# cation, that string is an entire client hostname, an 400# entire client IP address, or an entire mail address. Thus, 401# no parent domain or parent network search is done, 402# user@domain mail addresses are not broken up into their 403# user@ and domain constituent parts, nor is user+foo broken 404# up into user and foo. 405# 406# Patterns are applied in the order as specified in the ta- 407# ble, until a pattern is found that matches the search 408# string. 409# 410# Actions are the same as with indexed file lookups, with 411# the additional feature that parenthesized substrings from 412# the pattern can be interpolated as $1, $2 and so on. 413# 414# TCP-BASED TABLES 415# This section describes how the table lookups change when 416# lookups are directed to a TCP-based server. For a descrip- 417# tion of the TCP client/server lookup protocol, see tcp_ta- 418# ble(5). This feature is not available up to and including 419# Postfix version 2.4. 420# 421# Each lookup operation uses the entire query string once. 422# Depending on the application, that string is an entire 423# client hostname, an entire client IP address, or an entire 424# mail address. Thus, no parent domain or parent network 425# search is done, user@domain mail addresses are not broken 426# up into their user@ and domain constituent parts, nor is 427# user+foo broken up into user and foo. 428# 429# Actions are the same as with indexed file lookups. 430# 431# EXAMPLE 432# The following example uses an indexed file, so that the 433# order of table entries does not matter. The example per- 434# mits access by the client at address 1.2.3.4 but rejects 435# all other clients in 1.2.3.0/24. Instead of hash lookup 436# tables, some systems use dbm. Use the command "postconf 437# -m" to find out what lookup tables Postfix supports on 438# your system. 439# 440# /etc/postfix/main.cf: 441# smtpd_client_restrictions = 442# check_client_access hash:/etc/postfix/access 443# 444# /etc/postfix/access: 445# 1.2.3 REJECT 446# 1.2.3.4 OK 447# 448# Execute the command "postmap /etc/postfix/access" after 449# editing the file. 450# 451# BUGS 452# The table format does not understand quoting conventions. 453# 454# SEE ALSO 455# postmap(1), Postfix lookup table manager 456# smtpd(8), SMTP server 457# postconf(5), configuration parameters 458# transport(5), transport:nexthop syntax 459# 460# README FILES 461# Use "postconf readme_directory" or "postconf html_direc- 462# tory" to locate this information. 463# SMTPD_ACCESS_README, built-in SMTP server access control 464# DATABASE_README, Postfix lookup table overview 465# 466# LICENSE 467# The Secure Mailer license must be distributed with this 468# software. 469# 470# AUTHOR(S) 471# Wietse Venema 472# IBM T.J. Watson Research 473# P.O. Box 704 474# Yorktown Heights, NY 10598, USA 475# 476# ACCESS(5) 477