Mail app keeps opening automatically
Mac OS is 10.14.5. When I open my Mac, when I am doing anything else, the mail app opens automatically. No new mail, no any notification, it just pops up. I think the issue is about the gmail account, because when I close it, the problem solved. However, I can't just not use my gmail. Is there any solution on this? I saw something saying that go to the setting of google calendar, but that was one year ago. The layout of google has changed. Help me!
MacBook Pro 13”, macOS 10.14