K-9 Mail APK v24.0 · Latest Version for Android
K-9 Mail is a classic open-source email app for Android with multiple accounts, unified inbox, push mail and OpenPGP encryption.
- Version
- 24.0
- Updated
- Oct 18, 2026
- Size
- 10 MB
- Requires
- Android 6.0+
- Developer
- K-9 Mail / Thunderbird
- Category
- Communication
- License
- Apache-2.0
- Package
- com.fsck.k9
Screenshots
What's New in v24.0
- K-9 Mail version 24.0
- New:
- Signatures support HTML
- Reply offers Reply or Reply All
- Changed:
- Long account names fit in two lines
What is K-9 Mail?
K-9 Mail has been one of the best-known open-source email clients on Android for more than a decade, and it is now the base of Thunderbird for Android. It works with nearly any email provider over IMAP and POP3 and connects only to your mail server, with no tracking.
Key Features
- Multiple accounts and a unified inbox
- IMAP push and background sync
- Local and server-side search
- OpenPGP encryption with OpenKeychain
- No tracking: connects only to your provider
Getting Started
Add an account with your email address and password; K-9 detects the settings for most providers. For encrypted mail, install OpenKeychain and link it in the account settings.
Open Source and Privacy
K-9 Mail is developed in the open by K-9 Mail / Thunderbird and released under the Apache-2.0 license. The code is hosted at github.com/thunderbird/thunderbird-android, so anyone can check what the app does. The version on this page has no ads or tracking libraries flagged by F-Droid.
How to Install K-9 Mail APK
- Tap Download and get the K-9 Mail v24.0 APK (10 MB).
- Optional: compare the file’s SHA-256 checksum with the one on the download page.
- Open the file and allow your browser or file manager to install unknown apps if asked.
- Tap Install. Updates from the same source install over this one and keep your data, because they are signed with the same key.
Frequently Asked Questions
Is K-9 Mail free?
Yes. K-9 Mail is free and open-source software released under the Apache-2.0 license. It has no ads and no paid version is required to use it.
Is this K-9 Mail APK safe?
The APK on this page is the original file published in the F-Droid repository, unmodified. Its SHA-256 checksum is listed on the download page so you can verify it, and the full source code is public.
What Android version does K-9 Mail need?
K-9 Mail v24.0 requires Android 6.0 or newer.
Where can I find the source code of K-9 Mail?
The source code is available at https://github.com/thunderbird/thunderbird-android. You can read it, report issues or contribute there.
