On Tue, 2006-01-31 at 22:42 -0800, Tony Kay wrote:

How does dovecot handle this kind of conflict. I.e. how would one dovecot IMAP on server A detect that dovecot on server B had rewritten something like flags on the mailbox they are both accessing? I'm sure it doesn't leave the dot lock sitting around, since that would block mail delivery.

It just checks if mbox's mtime has changed. If it has, it checks if there are new mails or if it needs to do some other synchronization (mbox_dirty_syncs / mbox_very_dirty_syncs causes it to delay it as long as possible).

UW-IMAP also checks if mtime has changed, but instead of trying to figure out what changed it just disconnects the client with an "unexpected mbox change" error.