Mozilla has released a beta version of version 2 of its Thunderbird email client, which for the first time incorporates tagging.

The organisation has emphasised that the beta download is for testing purposes only, and is recommended for the testing community, or people who know what they're doing.

A number of new features have been incorporated, notably including message tags to make sorting and organising mail easier.

The theme and user interface have been updated to improve usability, and a session history allows you to navigate back through your current viewing session.

Folder views, support for extensions, offline management, and new mail notification alerts have all been improved. The new mail notification alert includes information including subject, sender, and message text.

There's now an option to mouse over a folder with new messages to see a summary of the new messages, as well as find as you type, so that messages are located more quickly.