Do you Support Sounds? How can I Customize Sound Notifications?
In order to customize the sound notifications, please follow these steps:
Accounts | tap the account you want to update | Custom Incoming Sounds and choose the new incoming mail sound. Note: Check you are not in silent mode, when checking sound notifications. Also, Android is able to play only one sound at a time, so if you receive notifications on your emails from more than one apps, only one sound will be played.