K-9 Mail
K-9 Mail is a 100% open source, privacy focused email client for Android
Mozilla Thunderbird
K-9 Mail is developed and provided by Mozilla Thunderbird.
Version16.1
Updated on
2025-10-21
Rating3.0
CategoryCommunication
Package namecom.fsck.k9
K-9 Mail Description
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.
Open up
Is K-9 Mail safe for my device?
Open up
Yes, K-9 Mail follows the Google Play content guidelines to ensure safe use on your Android device.
What is an XAPK file, and what should I do if the K-9 Mail I downloaded is an XAPK file?
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A file with .xapk extension is a compressed package file. It is a container file format that incorporates APK and additional associated files required for the installation.
The XAPK format was introduced to package the APK file and OBB file together for a seamless delivery and installation process.
XAPK format can help reduce the package size of application.
On mobile phones, users need to install the XAPK installer first, and then install XAPK files through that installer. You can find the installer here:https://apkcombo.com/how-to-install/. But on PC client, you just need to put the file on LDPlayer.
Can I play K-9 Mail on my computer?
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Yes, you can play K-9 Mail on your computer by installing LDPlayer, an Android emulator. After installing LDPlayer, simply drag and drop the downloaded APK file into the emulator to start playing K-9 Mail on PC. Alternatively, you can open the emulator, search for the game or app you want to play, and install it from there.
