Mail app on Mac keeps opening and popping up
My mail app keeps opening and popping up at random times, sometimes when I’m not even receiving any new messages. I have a MacBook Air 2017. This became annoying when I’m watching a movie or doing something full screen and the mail app opens, dividing the screen. When I close it, it often opens up again, just seconds after I closed this. Often this happens 3-4 times in a row. I don’t know how to turn this off.
MacBook Air 13″, macOS 10.15