Mozilla Mail Client – THUNDERBIRD.EXE
Thunderbird.exe is the executable for the Thunderbird email client by Mozilla. Thunderbird was designed to mail emailing safer by preventing or avoiding viruses. It also offers intelligent spam filters, a built in RSS reader, email quick search features, and integration with Mozilla's FireFox browser. More information can be found at http://www.mozilla.org/products/thunderbird/.
This file doesn't necessarily need to be running all the time. It can be launched when needed from Start > Programs or from your Firefox browser.
Safe
Mozilla