The server is a CentOS 5 install running Dovecot for imap access within an office LAN to about 5 computers using Thunderbird. There's only one mailbox, in the Maildir format, and about 20GB in size. One of the drives in the RAID 1 array failed recently and had to be replaced and re-synced.
Now, users are reporting strange IMAP issues from their mail clients, such as messages missing, deleted, or moved from folders.
How can I diagnose what the problem is? I haven't been able to replicate the problem myself and all I have is anecdotal evidence. It would be too easy to blame user error!