Mozilla Messaging team has released Thunderbird 3.0 Alpha 2 code named Shredder. Shredder Alpha 2 is a developer preview release that is being built on top of the next generation of Mozilla’s layout engine, Gecko 1.9. Shredder Alpha 2 is being made available for testing purposes only and is intended for developers and testing community.

What’s new in Alpha 2:

Integration improvements

• Shredder can import mail from Mail.app on Mac OS X
• Shredder theme looks more native on OS X
• OS X Address Book integration on by default
• Improved accessibility for screen readers
• Outlook Express import now copies SSL and port settings

Other features

• IMAP delete and undo operations are faster
• Forwarded messages are inline by default
• Replies allow to quote only selected text
• Purge button added to toolbar optionally

Platform improvements

• Extension authoring made easier by assigning IDs to most XUL elements
• Windows x64 builds now possible
• Several improvements to junk scoring subsystem

There were over 300 bug fixes in this release. You can download alpha 2 here.

Here are some of the known issues with alpha 2:

All Systems

• There will not be any automatic updates to this developer preview.
• Ensure extensions either come from a secure server using the HTTPS protocol or
  are digitally signed, or they will fail to install.
• The “Move To” sub-menu is empty (bug 432088)

Microsoft Windows

• Make sure Windows 95/98 compatibility mode is disabled for the Thunderbird executable. The setting will be inherited from previous Thunderbird installations if the original directory is over-written. Certain issues will go away once the compatibility mode is disabled. (Bug 381922)

Source: Mozilla Messaging.