As part of Mozilla’s new rapid release development process, the beta development channel has been updated with the third beta version of Thunderbird.  For information about Thunderbird Beta please visit:

• Download Thunderbird Beta: http://www.mozilla.org/thunderbird/all-beta.html
• Release Notes: http://www.mozilla.org/thunderbird/9.0beta/releasenotes/

For desktop users, if you previously installed a beta version of Thunderbird you will receive an automated update notification within 24 to 48 hours.