The plan for K-9 Mail 6.000 sounded simple enough: fix the various known issues with notifications for new messages. Yet, it took over 7 months and more than 350 individual changes for this version to be ready for release.


We ended up rewriting large parts of the code dealing with notifications. The user experience isn’t vastly different, but hopefully most of the annoying things that you had to put up with are gone now. Some examples:

  • When syncing a folder for the first time, the app no longer creates notifications. That’s a good thing. When setting up the app, you don’t want to get notifications for messages that are 2 years old but happen to be unread.
  • The app no longer creates notifications when you manually refresh the message list. However, you will still get notifications when manually refreshing a whole account or all accounts. This is so you don’t miss new messages in folders that aren’t currently displayed.
  • When displaying the message list screen, notifications for messages in that list are automatically removed. Previously, all notifications belonging to that account had been removed 😞
  • In earlier versions, going back after opening a message via a notification would open the folder the message belongs to. Now the Unified Inbox is opened (if the message is part of the Unified Inbox).
  • Notifications for new messages are now restored when the app is restarted. That’s useful e.g. after a device reboot.

We’ve also updated the user interface to configure vibration and the notification light color.

K-9 Mail 6.000 screenshot < K-9 Mail 6.000 screenshot

New features

The focus was on fixing issues related to notifications, but some new functionality still made it into this release:

  • Optionally show starred message count in side drawer
  • Allow specifying Reply-To addresses when composing a message
  • Support for exporting the debug log (in the menu under Settings → General settings → Debugging)

K-9 Mail 6.000 screenshot < K-9 Mail 6.000 screenshot

Fixed bugs

We fixed a ton of bugs! To be fair, some of those we introduced when rewriting the notification code (thank you beta testers for finding and reporting these ❤️). But we also fixed many old bugs. And we didn’t limit ourselves to just bugs related to notifications. For a detailed list, please consult the change log.


If you can’t find the new version on F-Droid or Google Play yet, just wait a few days. The new version will show up eventually.
If you absolutely can’t wait, download the APK from the GitHub release page: K-9 Mail v6.000.

Support & feedback

If you have questions about the new version, please join our support forum. It’s also a great place to provide feedback and have discussions about the future of the app.


If you have questions or comments, please let us know in this forum thread.