K-9 Mail
com.fsck.k9
Will K-9 Mail still install after September 30, 2026?
Enforcement starts in
Developer verification status for K-9 Mail
- Usually installed from
- F-Droid / GitHub
- Category
- Messaging
- Enforcement date
- 30 Sep 2026
What this means for K-9 Mail
The developer of K-9 Mail has registered this package name with Google. On certified Android phones, K-9 Mail keeps installing and updating normally — including from F-Droid / GitHub.
How to keep using K-9 Mail
Already installed? K-9 Mail keeps running. The block applies to new installs and updates.
Start the advanced flow now (it takes 24 hours): see the step-by-step guide.
Installing from a store app (F-Droid / GitHub)? The store itself must also be allowed — check it too.
Developer of K-9 Mail? Registration costs $25 (free for hobby apps limited to 20 devices).
FAQ
Will K-9 Mail stop working on September 30, 2026?
No. Already-installed apps keep running. What changes is installing and updating: if K-9 Mail is from an unregistered developer, certified phones in Brazil, Indonesia, Singapore and Thailand will block normal installs and updates.
Is K-9 Mail affected outside Brazil, Indonesia, Singapore and Thailand?
Not yet. Google plans a global rollout in 2027, so checking now helps you prepare.
How can I still install K-9 Mail if it is not verified?
Enable “Allow apps from unverified developers” in Developer options (24-hour wait), or install it from a computer with ADB.
Other messaging
Start the 24-hour clock today
The advanced flow takes a full day to unlock. Do it before you need it.
Step-by-step: install apps from unverified developers