One of databases got broken.
Coz of this the app reboots the device (or more hung it, and it reboots) when: I try to refresh mails or delete the database.
Tried to delete by:
- wiping data of the app by settings (reboot),
- wiping its data using Titanium Backup (reboot),
- deleting app using Android's Package Installer,
- deleting using Titanium Backup,
- deleting using Terminal,
- deleting file after file using Solid Explorer,
- deleting using TWRP's Terminal,
- deleting using TWRP's File Manager.
I could delete all other files of the app (apk, dalvik cache, non-databases from /data/data), but if I try to touch databases, device reboots...
That way I cannot use this app.