Covideo - Covideo is a Video Email Platform for Businesses that enables companies to communicate quickly and effectively with their customers.
Geary - Geary is an email application built for GNOME 3.
Junk Email Filter - Junk Email Filter is a front end spam filtering and virus blocking service for email servers.
Mailspring - Mailspring is a mail client for Mac, Windows and Linux.
BlueMail - BlueMail is an email management app for Android, iOS, and Windows.
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.