After the update to Mavericks, Mail.app got stuck and wouldn’t synchronise mails automatically with the server. Manually forcing the new mail reception worked.
The fix is very simple:
- Go to Mail -> Preferences -> Accounts and choose the IMAP account to fix.
- In the advanced tab, tick the box “Use IDLE command if the server support it”.
- That’s it! Synchronisation of IMAP should be fixed 🙂 Enjoy it!