You can add your own sounds that can be used for different notifications inside AltaMail.

Open the app settings (View) - "Email Management" section and then tap on "Email Notification Settings"
Tap on "Email Sounds" in the top of the edit notification screen to view the email sound settings
Tap on "Custom Sounds" in the bottom of the sound screen to add your own sounds.
Use the "+" button to choose sounds files from your local files in AltaMail, cloud servers, your Mac or PC (using WePrint) or other locations.
Tap on each sound file to create a notification and test that the sound is compatible with notifications. You should then see a notification and hear the sound. Check your iPhone/iPad volume and mute buttons.

Note: Sound files for notifications must meet the Apple format guidelines. Generally, this includes files of type aiff, wav, or caf file using the formats Linear PCM, MA4 (IMA/ADPCM), µLaw or aLaw. Sounds longer than 30 seconds will not play.

You can also use the microphone in the top of the custom sounds screen to record your own sounds.