If you love the older notification sound and would like to continue using it, simply download it to your device.
Next, place the sound file into your “Notifications” folder using the file manager. This varies between devices but usually is similar to:
Finally in BlueMail, tap More (o o o) | Notifications | Sound|Vibrate|LED | Incoming Sound | Custom Incoming Sound.
Other BlueMail sounds can be found on our SoundCloud