Mozilla Messaging has release Thunderbird 3.1 based on the Gecko 1.9.2 platform, was built by a community of passionate contributors, experienced developers, security experts, localization and support communities, and thousands of active testers.

Some of the new features:

• New Quick Filter toolbar
• New Migration Assistant
• Saved Files Manager
• Several fixes to improve upgrading from Thunderbird 2
• Several design improvements and corrections to the interface
• Stability, memory, and password handling improvements

For more information and to download please see the Thunderbird 3.1 Release Notes.

Source: Mozilla Developer’s News