…in a manner of speaking. The Firebird and Thunderbird Mozilla projects have both been working very well for me. In particular Firebird gets rid of the vein-poppingly infuriating UI decision to put ‘Close Tabs’ and ‘Close Other Tabs’ right next to each other, and when looking at your ‘Sent’ folder Thunderbird can actually display the recipient rather than the sender, which is always you. Thunderbird in particular seems a bit snappier when marking junk mail and deleting messages. And both seem stable on Win32 (XP) and Linux.