xref: /freebsd-11.0-release/contrib/sendmail/KNOWNBUGS

	     K N O W N   B U G S   I N   S E N D M A I L
			     (for 8.9.0)


The following are bugs or deficiencies in sendmail that I am aware of
but which have not been fixed in the current release.  You probably
want to get the most up to date version of this from ftp.sendmail.org	
in /pub/sendmail/KNOWNBUGS.  For descriptions of bugs that have been
fixed, see the file RELEASE_NOTES (in the root directory of the sendmail
distribution).

This list is not guaranteed to be complete.


* Null bytes are not handled properly in headers.

  Sendmail should handle full binary data.  As it stands, it handles
  all values in the body, but only 0x01-0x80 and 0xA0-0xFF in
  the header.  Notably missing is 0x00, which would require a major
  restructuring of the code -- for example, almost no C library support
  could be used to handle strings.

* Duplicate error messages.

  Sometimes identical, duplicate error messages can be generated.  As
  near as I can tell, this is rare and relatively innocuous.

* $c (hop count) macro improperly set.

  The $c macro is supposed to contain the current hop count, for use
  when calling a mailer.  This macro is initialized too early, and
  is always zero (or the value of the -c command line flag, if any).
  This macro will probably be removed entirely in a future release;
  I don't believe there are any mailers left that require it.

* If you EXPN a list or user that has a program mailer, the output of
  EXPN will include ``@local.host.name''.  You can't actually mail to
  this address.  It's not clear what the right behavior is in this
  circumstance.

* \231 considered harmful.

  Header addresses that have the \231 character (and possibly others
  in the range \201 - \237) behave in odd and usually unexpected ways.

* accept() problem on SVR4.

  Apparently, the sendmail daemon loop (doing accept()s on the network)
  can get into a weird state on SVR4; it starts logging ``SYSERR:
  getrequests: accept: Protocol Error''.  The workaround is to kill
  and restart the sendmail daemon.  We don't have an SVR4 system at
  Berkeley that carries more than token mail load, so I can't validate
  this.  It is likely to be a glitch in the sockets emulation, since
  "Protocol Error" is not possible error code with Berkeley TCP/IP.

  I've also had someone report the message ``sendmail: accept:
  SIOCGPGRP failed errno 22'' on an SVR4 system.  This message is
  not in the sendmail source code, so I assume it is also a bug
  in the sockets emulation.  (Errno 22 is EINVAL "Invalid Argument"
  on all the systems I have available, including Solaris 2.x.)
  Apparently, this problem is due to linking -lc before -lsocket;
  if you are having this problem, check your Makefile.

* accept() problem on Linux.

  Apparently, the accept() in sendmail daemon loop can return ETIMEDOUT
  and cause sendmail to sleep for 5 seconds during which time no new
  connections will be accepted.  An error is reported to syslog:

  Jun  9 17:14:12 hostname sendmail[207]: NOQUEUE: SYSERR(root):
			getrequests: accept: Connection timed out

  "Connection timed out" is not documented as a valid return from
  accept(2) and this was believed to be a bug in the Linux kernel.
  Later information from the Linux kernel group states that Linux
  2.0 kernels follow RFC1122 while sendmail follows the original BSD
  (now POSIX 1003.1g draft) specification.  The 2.1.X and later kernels
  will follow the POSIX draft.

* Excessive mailing list nesting can run out of file descriptors.

  If you have a mailing list that includes lots of other mailing
  lists, each of which has a separate owner, you can run out of
  file descriptors.  Each mailing list with a separate owner uses
  one open file descriptor (prior to 8.6.6 it was three open
  file descriptors per list).  This is particularly egregious if
  you have your connection cache set to be large.

* Connection caching breaks if you pass the port number as an argument.

  If you have a definition such as:

	  Mport,          P=[IPC], F=kmDFMuX, S=11/31, R=21,
			  M=2100000, T=DNS/RFC822/SMTP,
			  A=IPC [127.0.0.1] $h

  (i.e., where $h is the port number instead of the host name) the
  connection caching code will break because it won't notice that
  two messages addressed to different ports should use different
  connections.

* ESMTP SIZE underestimates the size of a message

  Sendmail makes no allowance for headers that it adds, nor does it
  account for the SMTP on-the-wire \r\n expansion.  It probably doesn't
  allow for 8->7 bit MIME conversions either.

* Paths to programs being executed and the mode of program files are
  not checked.  Essentially, the RunProgramInUnsafeDirPath and
  RunWritableProgram bits in the DontBlameSendmail option are always
  set.  This is not a problem if your system is well managed (that is,
  if binaries and system directories are mode 755 instead of something
  foolish like 777).

* 8-bit data in GECOS field

  If the GECOS (personal name) information in the passwd file contains
  8-bit characters, those characters can be included in the message
  header, which can cause problems when sending SMTP to hosts that
  only accept 7-bit characters.

* 8->7 bit MIME conversion

  When sendmail is doing 8->7 bit MIME conversions, and the message
  contains certain MIME body types that cannot be converted to 7-bit,
  sendmail will strip the message to 7-bit.

* 7->8 bit MIME conversion

  If a message that is encoded as 7-bit MIME is converted to 8-bit and
  that message when decoded is illegal (e.g., because of long lines or
  illegal characters), sendmail can produce an illegal message.

* MIME encoded full name phrases in the From: header

  If a full name phrase includes characters from MustQuoteChars, sendmail  
  will quote the entire full name phrase. If MustQuoteChars includes  
  characters which are not special characters according to STD 11 (RFC  
  822), this quotation can interfere with MIME encoded full name phrases. 
  By default, sendmail includes the single quote character (') in
  MustQuoteChars even though it is not listed as a special character in
  STD 11.


(Version 8.32, last updated 6/30/98)