Mozilla Thunderbird
Mozilla Thunderbird is a fully featured, secure and very functional email client and RSS feed reader. It lets you handle mail efficiently and with style, and Mozilla Thunderbird filters away junk mail too.
Licence: Freeware (Open Source)
Size: 17.6MB
OS:Windows
Download: http://www.mozilla.org/en-US/thunderbird/download/
Support: https://support.mozillamessaging.com/en-US/home