Apple mail occasionally opens

[NordmoleX]

I am a bit concerned. I am still quite new to MacOS, and something strange came up for the last few days. Occasionally Apple Mail shows on the screen. I have Apple mail running all the time, but usually minimized. Its not even if a mail comes in, its just random. Its also not often.

I checked with Malwarebyes and Etrecheck if anything comes up, but nothing. Cant really remember installing apps that could have done that. Anyone has an idea what that could be ?