When you receive a new email message, Thunderbird plays a sound to alert you. By default, it uses your operating system’s new mail notification, but you can change it to anything you like.
Change the New Mail sound
1. At the top of the Thunderbird window, click the menu and select In the menu bar, click the menu and select At the top of the Thunderbird window, click the , or click the menu button menu and select and choose .
2. Select thetab.
3. Select Use the following sound file.
4. Click, then browse to the folder on your computer that contains the .WAV audio file you want to use.
5. Double-click the sound file, then test it by clicking.
6. Clickto save your changes.