User defined sound for new emails in Android application

[Andi1]

I would like to hear if I received an email, a Signal message, an appointment et cetera.

[Jon]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.

[Wurftaube]

You probably haven't discovered it yet, but you can even set a separate ringtone for each email account under Settings -> Accounts -> Account xy -> Notifications -> Ringtone.