Mozilla Messaging has released the next version of Thunderbird on January 31st, 2012. Thunderbird 10.0 includes these changes:

• New ability to search the Web
• Improvements to email search
• Several fixes when drafting email
• and several other platform fixes

Existing Thunderbird user can update from within Thunderbird via Help > About Thunderbird or can manually download and install the latest version via getthunderbird.com site. Thunderbird 10 is also going to the build the new Thunderbird Extended Support Release (ESR) aka Thunderbird for  Enterprise users are based upon.

Lightning Users: You will need to update to Lightning version 1.2 for Thunderbird 10. From within Thunderbird go to the add-ons manager and click the Gear icon and select Check for Updates.

The next scheduled release will be on March 13th, 2012 with Thunderbird 11.