Users would be able to use tags and saved folders, much like the labels feature within Gmail, and the saved folders feature within Mac OS X's Mail client. This would make pulling up information on a specific topic much faster than searching by keyword.
Searching has also been enhanced. With similar "find as you type" functionality as found in Firefox, and instant search results as a query is typed. McGregor noted that many of the features requested in Thunderbird have been brought over from the popular alternative browser easily because they share the same code base.
This would also be true for the new Message History Navigation feature that adds back and forward buttons to the client. You can browse through messages just like in a Web browser. The functionality would also be independent of data type, meaning a user could switch between a RSS feed and mail message, for example.
Mozilla is also experimenting with a new webmail integration feature, and ships Thunderbird 2.0 with connectors for Gmail and .Mac out of the box. This would allow a user to easily set up either service without having to enter the technical particulars.
Of the development process, Mozilla claims about 2,500 users actively download its nightly builds, with about 55,000 using the beta regularly.