Since one of our customers updated their server courier does not handle IMAP connections properly any more. POP3 works without any problems.
When I try to test IMAP with telnet then it is always like this:
$ telnet domain.com 143
Trying 188.40.46.214...
Connected to domain.com.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE ACL ACL2=UNION STARTTLS] Courier-IMAP ready. Copyright 1998-2011 Double Precision, Inc. See COPYING for distribution information.
01 LOGIN test@domain.com test
Connection closed by foreign host.
I enabled debugging in the authdaemond but the output does not really help much:
Apr 12 23:10:04 servername authdaemond: received auth request, service=imap, authtype=login
Apr 12 23:10:04 servername authdaemond: authmysql: trying this module
Apr 12 23:10:04 servername authdaemond: SQL query: SELECT login, password, "", uid, gid, homedir, maildir, quota, "", concat('disableimap=',disableimap,',disablepop3=',disablepop3) FROM mail_user WHERE login = 'test@domain.com'
Apr 12 23:10:04 servername authdaemond: password matches successfully
Apr 12 23:10:04 servername authdaemond: authmysql: sysusername=<null>, sysuserid=5000, sysgroupid=5000, homedir=/var/vmail, address=test@domain.com, fullname=<null>, maildir=/var/vmail/domain.com/test, quota=0, options=disableimap=n,disablepop3=n
Apr 12 23:10:04 servername authdaemond: Authenticated: sysusername=<null>, sysuserid=5000, sysgroupid=5000, homedir=/var/vmail, address=test@domain.com, fullname=<null>, maildir=/var/vmail/domain.com/test, quota=0, options=disableimap=n,disablepop3=n
Right after the "Authenticated" line the output stops. There is no other message. And in no other log file I've checked I could find any other related message.
The system was updated from Ubuntu 10.10 to 12.04.
How could I get more information? Or does anybody have an idea what could go wrong here?
Best Answer
Looks like the connection handler process is crashing for some reason. I'd advise the user to downgrade to the version they were previously using, or upgrade all its dependencies. Reinstalling may also help.