The problem of Berkley DB 4.3 in Fedora Core 4 vs Berkley DB 4.2 in Fedora Core 3 hits Cyrus IMAP server also. Basically the server stops working showing mulptiple errors in the log:
Jun 26 20:01:44 mail imaps[3581]: DBERROR: critical database situation Jun 26 20:01:44 mail master[3582]: about to exec /usr/lib/cyrus-imapd/lmtpd Jun 26 20:01:44 mail lmtpunix[3582]: DBERROR ยด : db4 Jun 26 20:01:44 mail lmtpunix[3582]: DBERROR: critical database situation
The problem can be solved stopping the daemon and removing deliver.db and tls_sessions.db from /var/lib/imap and also erasing everything from /var/lib/imapd/db/