Big Sur 11.1 mail keeps showing the spinning wheel and won't quit

I updated my Macbook Air and ever since Ive noticed my mail won't close down, have to force quit every time. Now since this morning every time I try to send an email I get the spinning wheel and it never stops, so I can't send any mail. Please help
The same here. I've experienced the same problem with Mail (when trying to quit), Safari (when trying to open a new tab via keyboard) and other apps when trying to quit and also when trying to open Mail. Maybe there is a problem with the finder. The update to 11.2 and 11.3 beta didn't solve the problem. Sometimes the problem disappears for several hours and occurs on both my iMac 2019 and my MBP M1 2020. The issue is really annoying since the only solution is a long press to the power button.
Big Sur 11.1 mail keeps showing the spinning wheel and won't quit
 
 
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