How to detect out-of-sync condition

[Joseph Tam]

Cliff Hayes <chayes at afo.net> writes:

> I recently had a user whose mailbox had gone out of sync.
> Webmail and client inbox totals had become vastly different and response
> times had become unacceptable.
> A doveadm force-resync fixed the problem nicely.
> 
> This will no doubt happen again as we grow the service and I would like 
> to have some type of indication at the server level so I can run a 
> resync on a per-user basis as required.

Perhaps what you ought to look for is how are they getting out of sync in
the first place.  Assuming your webmail is a IMAP/POP client, I would look
at ways that your user's INBOX can be modified out of Dovecot's sight.
For example, does your LDA use dovecot's lda/lmtp, or do your users
run mail clients that directly manipulate mailbox files, or do you use
procmail/mail filters?

By closing off other avenues other than dovecot imap/pop/lda/etc.,
the indices will stay sync'd.

If you really have to do manual resyncing, comparing index/mailbox mtimes
might be one way to do it.

Joseph Tam <jtam.home at gmail.com>