Also, some interesting @thunderbird trivia: In 2004, blazing fast internet access wasn't nearly as widespread as it is now, so Mozilla offered to send installation CD-ROMs to users for $5.95.
With this year’s version, we’re delivering much more than just another yearly release. Supernova represents a modernized overhaul of the software – both visually and technically – while retaining the familiarity and flexibility you expect.
It's your first step into the future of Thunderbird.