[Dovecot] IMAP timeout problem

[Vasantha Narayan]

Hello,

We are running dovecot 1.1.2 on a Solaris 10 box.  We have been running the same configuration for about a year without a problem.  We have a different cert for POP and IMAP.

Recently we made two changes.  The cert for IMAP expired and we had to install a new one.  We applied some patches to the SAN disks that hosts the mail partition.  These changes were made over a weekend and the system was rebooted.  There were no errors in the logs and everything worked fine until the following Monday morning when IMAP connections increased.   When IMAP ports started getting hammered in the morning, IMAP clients started getting "IMAP time out" errors.    When this error occurs, IMAP freezes and IMAP clients such as, Thunderbird and Squirrelmail  are not able to connect to the IMAP server (both IMAP and IMAPS).   We cannot get a telnet connection to the IMAP port or a openssl connection to the IMAPS port.  Kill -HUP of the dovecot server solves the problem.  But again, when the usage increases, the problem surfaces again.  There is no problem with POP or POPS.  It continues to function normally while IMAP times out and freezes two or three times a day.

Any clue where the problem might be?  The debug log does not have any useful pointers.

Thanks.

Vasantha