There are a couple of ways to do the same task. '''Via in app settings''' Navigate to settings > account > notifications * Set 'new mail ringtone' to none, or * a. Tap 'messages' under the 'notification categories' section. * b. Toggle 'set as silent' or set the ringtone to 'none' You can set also set quiet time hours so you don't get notifications at night Navigate to settings > general settings > notifications Enable quiet time and set the desired time window. '''Via standard android notification settings.''' # Long press the Thunderbird launcher icon # Tap app info # Tap manage notifications # Tap 'messages' under your mail account name # Either toggle 'set as silent' or set the ringtone to 'none'