K-9 Mail is an open source email client with support for multiple accounts, search, IMAP push email, multiple folder sync, markup, archive, signatures, BCC-self, PGP / MIME, and more. Install "OpenKeychain: Easy PGP" app to encrypt / decrypt your emails using OpenPGP.K-9 is a community developed project. If you're interested in helping make the most popular open source email client on Android even better, join us! You can find our bug tracker, source code, we are always happy to welcome new developers, designers, documenters, bug finders and friends. We don't care if you tell the world you're frustrated, but if you use our bug tracker, we have a better chance of fixing whatever is causing you difficulties.
Required Android Versions : Ice Cream Sandwich [4.0.3–4.0.4] - Jelly Bean [4.1–4.3.1] - KitKat [4.4–4.4.4] - Lollipop [5.0–5.0.2] - Marshmallow [6.0 - 6.0.1] - Nougat [7.0 – 7.1.1] - Oreo [8.0-8.1]