Uninstall

Uninstall it from Windows, under Settings → Apps → EpistulaMail.

The uninstaller removes the program. To also erase the data:

1. Delete the %APPDATA%\br.com.epistula.desktop folder.
2. In Credential Manager → Windows Credentials, remove the entries of the epistula service.
3. If you want, remove EpistulaMail’s access at myaccount.google.com/permissions.

Your messages stay on your email server.