[Dovecot] IMAP

[Jason Lock]

We are using version 1.2.17 and recently are experiencing major issues with performance, which we believe have isolated to IMAP sessions.

We have 3 servers running Dovecot, with a central store shared via NFS.  Things have been running quite well for months now, with the latest issues appearing within the last week.

As an experiment have 2 of the server running and only accepting POP3 connecitons no IMAP, and the 3rd server only accepting IMAP connections and no POP3.

When the issue occurred today, stopping dovecot on the IMAP only server allowed POP3 to resume to normal operations 5-10 minutes later.  Leaving IMAP disabled for a period of time (about 30 mins) and then re-enabling seemed to worked the first time.  Subsequent times, the issue appeared shortly after re-enabling IMAP.

Our webmail solution connects via IMAP, so when disabled this also impact clients using the webmail.

Running only POP3 while IMAP is disabled we do not appear to have any issues.

At this point, looking for any advice.  We believe the number of devices utilizing IMAP has increased significantly for us, and whether or not a specific device is the cause we have not been able to determine.

Anyone else experiencing a similar problem that appears related to IMAP?