On Wed, 2008-09-10 at 10:29 +0200, Jan van den Berg wrote:
We run 1.1.3 and I use Outlook to connect to my IMAP box and a couple of times per day (randomly) when I click certain folders IMAP will start retrieving ALL headers for that folder again ('retrieving new headers')!
Typically that means that the mailbox's UIDVALIDITY has changed. Or the messages get assigned new UIDs for some reason (e.g. Dovecot sees that they're gone, later sees them again). You could verify these by using e.g. rawlog (http://wiki.dovecot.org/Debugging/Rawlog) and seeing if the UIDVALIDITY value after SELECT command changes and if the returned UIDs get changed.
Do you do anything on the server with dovecot-uidlist files? Or dovecot.index* files? Like deleting them once in a while as someone was doing in a cron job? :)