[Dovecot] Issues w/ Apple devices after migration to dovecot

[Armistead, Kurt]

Hi guys.
Recently we've moved our old (and I mean _really_ old) mailserver to a new
hardware. Since I had quite some time on my hands, I decided to switch
from courier to dovecot. Transition went pretty smoothly and the users
experienced just a few hours' blackout.

Only trouble now is that, after re-configuring some IOS handsets and
tablets, not all messages are displayed correctly.
For example, I had a long existing mailbox (roughly 1600 emails in INBOX
and about a dozen other folders) that showed up perfectly on my iphone.
Now it's been synced to the new dovecot server via imap and a whole month
of messages seems to be missing. I checked on the server, via webmail and
with outlook and everything is where it should be. The problem shows up on
Apple devices (same thing happened on a couple of ipads).

I haven't tried rebuilding the index or wiping out a phone to see if that
resolves the problem, but before I do that I'd like to know if anyone
experienced the same issue and how they fixed it

Thanks!

Kurt