K-9 Mail has controllable debug logging. Users can activate logging to help diagnosing problems and errors.
At the accounts screen of K-9 Mail press the menu button, then choose "Settings". Under the heading "Debugging" check the "Enable debug logging" checkbox. Hit the back button twice to save the changes.
If K-9 is crashing, don't worry about about enabling debug logs.
Do whatever causes the problem/error.
To fetch the debug log you can either attach the device to your PC and use the tool
adb from the Android SDK or you can use the application
aLogcat to display the debug log on the device.
To capture the debug log in a file named
k9-log.txt, enter the command:
adb logcat -d -v time k9:V '*:S' AndroidRuntime:E > k9-log.txt
aLogcat (from Google Play)
aLogCat. The app WON'T work with Android 4.1 and newer. If you have root see here: CatLog.
Apply as a regular expression?, and press "Okay".
It's ok to remove your password from the debug log. Other than that, please give us as much of the log as you possibly can.
Important: Include the exact version number of your installed K-9 Mail in the bug report. Read GetVersionNumber if you need help on finding out which version of K-9 you're running.