We've been following the beta releases of Mozilla's e-mail application Thunderbird 3 pretty closely over the last few months. It's a terrific free, cross-platform, open source alternative to the native e-mail apps that come bundled with Windows and Mac OS X. Thunderbird 3 also integrates nicely with Gmail, making it a great option for people who want to stick with their Web-based email but want the additional features of a desktop email app.
Mozilla released Thunderbird 3 Beta 4 this week, and it sports more than 200 changes over the past beta release, including new search tools, tabbed email messages, and better IMAP folder synchronization. I've been playing around with the new beta version for a couple of days now and I like what I've seen so far.
