Descriptions : With pEp you organize all existing mailboxes such as Gmail, iCloud, Outlook, Office365, Yahoo, AOL, IMAP or Exchange in a single Android app.
With fast encryption, different views, a uniform inbox and many configuration options, pEp covers almost all requirements. pEp makes email encryption just as easy as Signal makes encryption for messengers.
Features :
+ Data protection by default
+ End-to-end encryption in your existing accounts
+ Enterprise ready on all your devices
Required Android Versions : Lollipop [5.0–5.0.2] - Marshmallow [6.0 - 6.0.1] - Nougat [7.0 – 7.1.1] - Oreo [8.0-8.1]