Mail App Popups

Whenever I have my Mail app open on my MacBook, it will occasionally pop up on the side randomly whenever I'm working, forcing me to x out the window and forget where I left off. However, when I quit the app, it doesn't show itself until I turn it back on. It doesn't show itself when I have it on a different window either. Is there a way to prevent the app from popping up from the side?

Technical specs:

Mail version 13.4