http://www.mozilla.com/en-US/thunderbird/
What's New in Thunderbird 2.0.0.4
* Release Date: June 14th, 2007
* Security Update: The following security issues have been fixed.
* New Language: Korean is now available.
* Earlier Changes: For information about previous changes, please see the Thunderbird 2 Release Notes.
* Thunderbird 2 Features: For an overview, please see Thunderbird 2 Features.
The Rumbling Edge has a more detailed list of notable bug fixes.
