Mail App Pop Up During Full Screen

[python0704]

I have had this problem for a while, since release of Catalina as far as I can remember. But it became more annoying recently when I try to stream Disney+. Mail app frequently showed up itself especially during full screen video. I wasn't hitting any keys. It just took up the right half of the screen. It also happened sometimes when I use Word full screen. There is no new email arriving in the inbox (not sure about other folder). And if I wasn't watching full screen, Mail would just position itself on top of every other window, still annoying but less compared to full screen situation. Can anyone help me fix this? Thanks a lot.

 

[nnavas13]

That happens to both my brother and me too. Very annoying.
We haven't found a way to fix it.

 

[Taz Mangus]

The few discussions I read on this subject suggest that one reason why the pop up happens is because there is a connection issue. If you turn on mail logging at the time the pop up happens you could see if a connection issue is happening (Mail->Window->Connection Doctor, enable Log Connection Activity). Another user suggested in the case where gmail is being used, remove the gmail account and then add it back in as a other type account instead of as a gmail account.