To turn off notifications in Thunderbird:

Turn off Notifications

  1. Go to Tools > Options…
  2. Click on General at the top of the options screen.
  3. When new messages arrive:
    • Click on General at the top of the options screen.
  4. When new messages arrive:
    • Unselect Show an alert.
    • Unselect Play a sound.
    • Unselect Show an alert.
    • Unselect Play a sound.