If I delete multiple emails, the app crashes

Are you using an older version of Android? A beta has recently been released that fixes crashes when retrieving images from large emails. It will make it's way into the next stable release soon. I suspect It may resolve the issue for you. https://github.com/thunderbird/thunderbird-android/releases/tag/THUNDERBIRD_18_0b3 If the issue is still present after the next update, or you think the issue is different, please complete a bug report on github with a debug log attached. Submit bug report here: https://github.com/thunderbird/thunderbird-android/issues Guide to collect debug log: https://thunderbird.github.io/thunderbird-android/docs/latest/user-guide/troubleshooting/collecting-debug-logs.html