We've seen two issues come up with Dovecot LDA, both of which have caused us problems:
If the user's home directory does not exist, or is not owned by them, deliver fails and causes the mail message to bounce back to the originator. In our environment this happens when our user is moved to another server (where we move their files, but for up to 24 hours afterwards, continue to re-mail their /var/mail INBOX). This no longer works because the user has no home directory, causing deliver to fail with "Permission denied" when attempting to create their home directory for the purposes of creating INBOX index files.
If the user is over quota (in their home directory), deliver fails with a temporary error, causing requeues until the user is back under quota (which in our environment could be a long time, days). Since we've never had quotas on the user's INBOX (in /var/mail), this is a problem for us.
I'd propose for both of these cases that deliver issue WARNING messages to its logs, and simply not create index files for the INBOX. If the INBOX index files already exist, and the user is over quota in /home, neither deliver nor any other Dovecot process should attempt to update them, and instead issue WARNING messages. This allows the e-mail to be delivered instead of requeued, or worse yet, rejected. Index files are supposed to make things perform better, not worse, in ALL cases. :)
--
Steven F. Siirila Office: Lind Hall, Room 130B Internet Services E-mail: sfs@umn.edu Office of Information Technology Voice: (612) 626-0244 University of Minnesota Fax: (612) 626-7593