Mailpile

Mailpile is a free, open source e-mail client for Mac, Windows an Linux operating systems that lets users control their e-mails like never before. Unlike popular e-mail clients online, it attempts to make e-mail communications safe, secure and private. With OpenPGP signatures and encryption, it keeps your correspondence private, even if your computer is stolen. Users host Mailpile on their laptop or desktop themselves and there are no ads to be seen. All of this, packaged with fast speeds and powerful internal searches, makes Mailpile one of the most transparent and open e-mail clients on the market.