If you use Entourage as a mail client and access your mail via IMAP, you may get error messages reading: “Lost mailbox lock” or similar. The reasons for this are somewhat arcane, but the fix is simple:
- Pull down Tools | Accounts and double-click the affected account name.
- Click the Options tab.
- Uncheck the box labeled “Send commands to server simultaneously.”
Note, this fix does not work in all cases. The problem affects IMAP only — not POP. Birdhouse does not officially support IMAP with Entourage for this reason. Other mail clients are able to do IMAP with Birdhouse just fine. More information here.