How To Disable Thunderbird Popup Notification

If you are, like me, annoyed by the popup notification in Thunderbird, the following instructions show how you can disable it.

1. Open Thunderbird and go to “Preferences.”
2. Go to the “Advanced” tab and click on the “Config Editor” button.

Click the button “I accept the risk” to proceed.

3. At the search field, type mail.biff.show_alert.

4. Double-click the mail.biff.show_alert entry to toggle the value to “false.”

5. Close all windows and restart Thunderbird. That’s it. The annoying popup notifications are now gone.