MacBook Pro running 10.11.6. I've tried everything: unchecking "Do Not Disturb", checking sound level, checking "notifications" in mail. I've also noticed that sometimes the "Your mail has been sent" message doesn't come on after sending an email either, but that's only happened a couple of times. Not having the whoosh is driving me nuts. There has to be a solution to this. HELP!
MacBook Pro (13-inch Early 2011), iOS 10, 10.11.6