A warning to Thunderbird 3.1.x users the last release is coming on April 24 when the 3.1.x branch will finally be retired. This comes nearly a year after Thunderbird 5 was released last spring and is almost twice as long as Mozilla normally continues to provide support of older versions after a major release. Further starting with Thunderbird 13 on June 5, 2012, minimum requirement for Windows will change from Windows 2000 to Windows XP SP2. For organizations or individuals who are not able to update to the newer versions of Thunderbird due to older hardware and/or operating systems, there is the Thunderbird Extended Support Release 10.0.x builds. These will continue to be supported and updated through the rest of 2012. While support for Thunderbird 3.1.x will be ending, the application will still be useable after April 24th. However, there will no longer be security or stability updates released.