The parentheses in the subject are due to referral to this discussion on the mailing list: http://dovecot.org/list/dovecot/2012-February/063851.html

At first I thought I found the problem, but then realized this was 2012 and the suggested patch already is applied in dovecot.

I also have segault messages in my kernel log; not too many, but it was enough to dig for it:

Wed Jun 25 08:29:05 2014 auth[17590]: segfault at 10 ip 00007f02ad5e8e56 sp 00007fff932f9250 error 4 in auth[7f02ad5d3000+40000] Mon Jun 30 16:11:41 2014 auth[12501]: segfault at 10 ip 00007fc6a1fefe56 sp 00007fff276e6ea0 error 4 in auth[7fc6a1fda000+40000] Sat Jul 5 13:11:32 2014 auth[15603]: segfault at 10 ip 00007f6447a6be56 sp 00007fff09c48020 error 4 in auth[7f6447a56000+40000] Tue Jul 8 05:08:21 2014 auth[30071]: segfault at 10 ip 00007ff22656ae56 sp 00007fff26b017f0 error 4 in auth[7ff226555000+40000] Mon Jul 21 14:25:28 2014 auth[30918]: segfault at 10 ip 00007fe1fc817e56 sp 00007fff7e654f20 error 4 in auth[7fe1fc802000+40000] <--- Wed Aug 13 18:56:31 2014 auth[27593]: segfault at 10 ip 00007ffbf8ce8e56 sp 00007fffe0157f70 error 4 in auth[7ffbf8cd3000+40000] Wed Aug 13 18:57:59 2014 auth[24264]: segfault at 10 ip 00007f2df31bde56 sp 00007fff094263c0 error 4 in auth[7f2df31a8000+40000]

The last 2 entries are a result of me being able to reproduce the problem, the 3rd last is the only one I was able to track down (due to log rotation)

I tracked the problem down to a contact form of a website of one of my customers. whenever used, the segfault gets triggered. Nevertheless, the message always gets delivered.

So we are talking about the marked line; the corresponding log entries from mail.info:

Jul 21 14:25:29 mail postfix/smtpd[27590]: connect from unknown[<webserver ip>] Jul 21 14:25:29 mail dovecot: auth: Fatal: master: service(auth): child 30918 killed with signal 11 (core dumps disabled) Jul 21 14:25:29 mail postfix/smtpd[27590]: warning: unknown[<webserver ip>]: SASL DIGEST-MD5 authentication failed: Connection lost to authentication server Jul 21 14:25:29 mail dovecot: auth-worker(27595): mysql(127.0.0.1): Connected to database mail Jul 21 14:25:29 mail postfix/smtpd[27590]: D4D8E44752: client=unknown[<webserver ip>], sasl_method=CRAM-MD5, sasl_username=<existing account and working account> Jul 21 14:25:29 mail postfix/cleanup[27598]: D4D8E44752: message-id=id@doma.in Jul 21 14:25:29 mail postfix/qmgr[13349]: D4D8E44752: from=server@doma.in, size=2680, nrcpt=1 (queue active) Jul 21 14:25:29 mail postfix/smtpd[27590]: disconnect from unknown[<webserver ip>] Jul 21 14:25:29 mail dovecot: lmtp(27600): Connect from local Jul 21 14:25:30 mail postfix/lmtp[27599]: D4D8E44752: to=info@doma.in, orig_to=contact@doma.in, relay=<mailserver fqdn>[private/dovecot-lmtp], delay=0.19, delays=0.07/0.04/0.04/0.04, dsn=2.0.0, status=sent (250 2.0.0 info@doma.in MrY+OdkizVPQawAAMrkmwA Saved) Jul 21 14:25:30 mail postfix/qmgr[13349]: D4D8E44752: removed Jul 21 14:25:30 mail dovecot: lmtp(27600, info@doma.in): MrY+OdkizVPQawAAMrkmwA: msgid=id@doma.in: saved mail to INBOX Jul 21 14:25:30 mail dovecot: lmtp(27600): Disconnect from local: Client quit (in reset)

contact@doma.in is a virtual address which gets forwarded to info@doma.in (/etc/postfix/virtual).

The used CMS is PyroCMS (v2.2.3) - the version is not up2date, but nevertheless the CMS might be the one to blame, a service should not segfault. Some packages are to be updated, as well as the CMS; but I am willing to wait to provide information, which leads to the problem, as I cannot switch between different versions on my productive system for the sake of gaining debug information.

I hope that someone has any kind of clue and is willing to resolve that issue with me, asking me for the necessary information to do so.

Thanks in advance!