K-9 Mail is an open-source (Apache-2.0) Android app by thunderbird. The APK we host is 10 MB, it needs Android 6.0 or newer, and it declares 16 permissions.
The file on this page is K-9 Mail 24.0, 10.39 MB, and it installs on Android 6.0 and newer.
We compared the signing certificate of this build with the certificate recorded the first time com.fsck.k9 entered the site, and published both the file's SHA-256 and the certificate's fingerprint above so you can check the download yourself. That comparison says the file was not repackaged by someone else; it is not a review of what the app does.
The manifest inside the APK declares 16 permissions, including access to the camera and your contacts. Android asks you to approve those the first time the app needs them.
Its licence is Apache-2.0. We took this build from F-Droid, and the source for this exact version is linked below.
We do not show a star rating or an install count for this page: we have no measured figure for either, and a number we cannot source is worth less than an empty field.
- Version
- 24.0
- Size
- 10.39 MB
- Requires Android
- API 23
- Package
- com.fsck.k9
- Signature checked on
- Oct 20, 2026
- Where this file came from
- F-Droid
- Licence
- Apache-2.0
- Source code
- Source for this version
File SHA-256: 0f9dd57fbd06dddfd8bcf7de6106d27fa0f0297793193828c4eac904518b1e05
Signing certificate (SHA-256): c430665e3662253b2078dcda350c2c6ce44d915a3d8a147b63ced619bb9e8576
We check that this file carries the same signing certificate as earlier releases of the same package. That shows the APK was not repackaged by someone else — it is not a security review of the app.
Declared permissions
- CAMERA
- READ_CONTACTS
- POST_NOTIFICATIONS
- RECEIVE_BOOT_COMPLETED
- READ_SYNC_SETTINGS
- ACCESS_NETWORK_STATE
- INTERNET
- VIBRATE
- WAKE_LOCK
- FOREGROUND_SERVICE
- FOREGROUND_SERVICE_DATA_SYNC
- FOREGROUND_SERVICE_SPECIAL_USE
- SCHEDULE_EXACT_ALARM
- USE_BIOMETRIC
- USE_FINGERPRINT
- com.fsck.k9.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Screenshots
