Just as Firefox has been moved onto an accelerated release schedule, so Mozilla has increase the speed at which updates are released for its email client, Thunderbird. At any one time there are three different versions of Thunderbird available – the stable release, the beta version of the following release (this version of the application), and the alpha preview of the subsequent version called Earlybird.

For day to day use, it is recommended that most people stick with the stable release that is made available in the standard release channels, while those who like to live right on the cutting edge and experience all the latest feature may like to take a look at the Earlybird alpha. The problem with alpha software is that it can often be unstable, but by opting to work with the beta version of Thunderbird, you get the best of both worlds; a sneak peak at what is to come in future versions, but nothing so experimental that it is unreliable.

It is important to note that while the Earlybird alpha can be installed alongside an existing copy of Thunderbird, installing the beta will overwrite any stable version that is already installed. This beat version is primarily a bug fixing release and many of the problems that have been found in version 13 of the email client have now been fixed.

After Mozilla's recent announcement that Thunderbird is entering its "extended support phase", which basically means it'll only be officially maintained with minor bug fixes and security updates going forward.

This is the latest Thunderbird beta, now v38. New features/changes include:

- Filter sent messages (bug 11039)
Support Internationalized domain name URLs for RSS feeds (Bug 1018589)
Filter messages when archived (bug 479823)
Enable search in multiple/all address books (bug 170270)
Show expanded columns in folder pane (bug 464973)
Add a Learn more link to the support page in feeds subscribe dialog (bug 1053782)
Allow file-per-message (maildir) local message storage (bug 845952)
Support Yahoo! Messenger chat protocol (bug 955574)
OAuth2 can be selected for gmail accounts in advanced and manual account configuration (bug 849540)
- Add reading position marker line to conversations (bug 760762)
The editor for twitter should show inputtable character count (bug 736002)


The Beta version of Thunderbird only brings small incremental fixes and improvements.