The next major release has now reached stable state and is available for download. The important new features in 0.5 are: full support for shared folders and namespaces, Internationalized Domain Names (IDNA) as well as SMTP Delivery Status Notifications. The UI for managing IMAP folders has changed a bit and provides new space for further extensions and plugins.
More... (http://sourceforge.net/news/?group_id=139281&id=296168)