Thunderbird 15 Beta is now available for download and testing. Thunderbird is a free, open source, cross-platform e-mail and developed by the Mozilla Foundation. what’s new in this beta version of thunderbird?
Integration of Chat with unified global search
Do Not Track option has been added
New Australis User Interface
Ubuntu One has been added to the list of online storage providers for Filelink
Various fixes and performance improvements
Download Thunderbird Beta