While many users of Mozilla's Firefox open source browser and Thunderbird open source e-mail engine are hip to useful Firefox extensions and efficiency tips, there are a lot of really useful add-ons for Thunderbird too. These can help you search through your e-mail more effectively, allow you to browse new messages within other applications, integrate how you use Firefox and Thunderbird together, and much more.
In this post, I'll round up a series of useful Thunderbird add-ons that I use. These can save you much time and hassle.