[Dovecot] Debugging doveadm expunge

Hi,

I'm a recent convert to dovecot, and in general it is all working fine.

However, I have a number of cron jobs set up to purge old messages from mailboxes. These don't seem to be doing what I would expect.

Is there any way of debugging this process? Some way of seeing what messages it's checking, and why each one matches or fails to match?

For example, I'm running this:

doveadm expunge -u andy mailbox "News Reports" savedbefore 90d

from the crontab of user 'andy'. I'd expect the specified folder to only contain 90 messages (I get one 'News Report' per day) but in actual fact there are 1428 in there!

Any advice would be appreciated.

Thanks

Andy