…Mozilla Thunderbird 3 that is! And Mozilla promises that its email software that is often the choice of geeks is “faster, flexible, and more secure.”
A new tab feature allows users to load emails in separate tabs, just like in a Firefox browser. The improvement in its search capability speaks to more filtering and timeline tools to assist users in finding emails more efficiently.
Another feature is the Message Archive, essentially a storage place for emails that you don’t want to send to trash or keep in your inbox. Changing the appearance of your Thunderbird interface is also an added feature so users can e.g. change their ‘skin’ to suit them.
Thunderbird 3 also comes with improved Mail Account Setup Wizard, One-click Address Book, Attachment Reminder, Activity Manager, Phishing Protection and more. Check for the full list of features here.
Source:
http://www.mozillamessaging.com/en-US/thunderbird/features/#tabs-search