I have issue with Teams notifications. Although I set both kind of notifications, I only received banner notification. The worst think is the guests of my group do not receive any kind of notification.
In my case the problem is that mails go to spam box but guests don't receive anything. Below I add strange spam message.
I’ll test email delivery of notifications here shortly but keep in mind you only get email notifications if you are away from teams for about 5 minutes or not logged in. If you see the banner notifications then your actively on the computer with teams and it knows that and won’t send email since it knows your were available to see the banner.