1.

Protonmail

Email by hb882
ProtonMail Desktop is an unofficial app that emulates a native client for the ProtonMail e-mail service. NOTE: This is only to provide appimages, I am not the developer.
AppImage
Score 50%
50 Likes
50 Dislikes
Nov 25 2018
2.

Thunderbird - Appimage 45.4.0

Email by AJSlye
Thunderbird is a free email application that’s easy to set up and customize - and it’s loaded with great features! NOTE: This is only to provide appimages, I am not the developer.
AppImage
Score 50%
50 Likes
50 Dislikes
Jun 26 2018