16.1Version
5,000,000+Downloads
5.0+Android
EveryoneRated
Feb 10, 2026Updated

Screenshots

K-9 Mail screenshot 1K-9 Mail screenshot 2K-9 Mail screenshot 3K-9 Mail screenshot 4K-9 Mail screenshot 5K-9 Mail screenshot 6K-9 Mail screenshot 7K-9 Mail screenshot 8K-9 Mail screenshot 9

About K-9 Mail

K-9 Mail is a 100% open source, privacy focused email client for Android

K-9 Mail is an open source email client that works with basically every email provider.

Features

* supports multiple accounts
* Unified Inbox
* privacy-friendly (no tracking whatsoever, only connects to your email provider)
* automatic background synchronization or push notifications
* local and server-side search
* OpenPGP email encryption (PGP/MIME)

Install the app "OpenKeychain: Easy PGP" to encrypt/decrypt your emails using OpenPGP.


Support

If you're having trouble with K-9 Mail, ask for help in our support forum at https://forum.k9mail.app


Want to help?

K-9 Mail is now part of the Thunderbird family and remains a community developed project. If you're interested in helping to improve the app, please join us! You can find our bug tracker, source code, and wiki at https://github.com/thunderbird/thunderbird-android
We're always happy to welcome new developers, designers, documenters, translators, bug triagers and friends.

Ratings & Reviews

3.1
99.9K ratings
11.1K reviews
5
36%
4
12%
3
10%
2
10%
1
31%

App Information

Package Namecom.fsck.k9
Version16.1
UpdatedFeb 10, 2026
Downloads5,000,000+
Content RatingEveryone
Android Version5.0+
PriceFree
DeveloperMozilla Thunderbird

What's New

v16.1
Feb 10, 2026

K-9 Mail — Various bug fixes and performance improvements.