How to detect out-of-sync condition

[Cliff Hayes]

Hello list,

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.
However, I don't know what to look for.
I did not see any signs of the problem on the server - but perhaps I did 
not know what to look for.

The only other alternative is for me to do a global resync in the 
cron.daily but my fear is that this won't scale well for thousands of users.

Please advise.

Thanks in advance.