Can't turn off annoying new mail sound
I have a new MacBook Air running the current version of Monterey. No matter what I do I can't turn off the sound when I get a new email. Even with notifications for mail turned off in the notification center, and sounds for new mail set to none in email preferences, I still get an annoying bonk type sound. If I try and change the new mail sound in mail preferences, it doesn't change - I still get this "bonk" kind of sound. It's very annoying. Any ideas?
MacBook Air 13″, macOS 12.2