Mailspring - Mailspring is a mail client for Mac, Windows and Linux.

Discourse - Discourse is an open source discussion platform built for the next decade of the Internet.

Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

Forumbee - Forumbee offers community forums for discussions, feedback and Q&A.

The Bat - The Bat! is a secure desktop email client for Windows, designed to protect your correspondence against third-parties and to save your time.

Directly - Directly provides on-demand customer service apps.