
Although the program remained one of the key players on the market of email applications for years, its popularity started to decline after Mozilla discontinued the work on new versions, which forced many users to choose Microsoft Outlook® instead. The program offers advanced email exchange functionality, supports multiple accounts and identities, flexible email sorting and filtering, message grouping and labeling, features a powerful Bayesian filter to cut off spam messages and offers a host of other powerful functions. Completely free and open source, it is available to users on various platforms, including Windows, Mac OS X and Linux, not to mention unofficial ports to more exotic operating systems, such as OpenSolaris and FreeBSD. Mozilla Thunderbird® is one of the major alternatives to Microsoft’s email applications and PIM tools.
