[Dovecot] Dovecot service not responding after about a week of uptime

Hello,

I am running a dovecot 2.1.13 server and lately it stops responding after about a week of uptime. Simply restarting the dovecot service solves the issue.

I tried to look a bit in my maillog file but did not find anything obvious. During the time when the server is not responding I can still see imap-login entries from the connection attempt by my email client. Any help about how to diagnose the problem would be appreciated.

Thanks,

Matthieu