IMAP not seeing old mail present on filesystem

[Chris Pepper]

All,

     I have run a small mail service based on Cyrus IMAP for a few 
years. The (CentOS 5) server I've used for the past couple years failed 
last week. I brought up a new CentOS 5 system on a new Linux server, 
installed cyrus-imapd-2.3.7-7.el5_4.3, mounted the old /var disk 
(actually one of 2 mdadm submirrors), and copied /var/spool/imap over to 
the new /var FS. It's running CentOS' cyrus-imapd-2.3.7-7.el5_4.3 RPM.

     Unfortunately, for many users (all but me?), mail clients (at least 
Apple's Mail.app and SquirrelMail) don't show any messages from before 
the migration in INBOX. When I grope around in /var/spool/imap/user, I 
see the old message (with high numbers) and the new messages (starting a 
new sequence from 1).

     I know there are last-message counters in the cyrus.* files, so 
would resetting those have caused IMAP to start storing new messages 
from 1. and vanish the old ones? I don't know how those could have been 
cleared for at least 6 users simultaneously. Presumably it happened for 
all, and I just fixed it for myself somehow.

     More importantly, I don't know how to make the old messages 
accessible to my users via IMAP (I can give them the files, but that's 
quite awkward). chk_cyrus agrees with IMAP clients about message counts 
(very low). I have tried reconstruct with various combinations of 
"-rfx", and "quota -f", but not found any way to make it show the old 
messages.

Any suggestions?

Thanks,

Chris