Is it just me, or has anyone else noticed that Apple Mail no longer permits multiple compose windows? I recently noticed that if I have a message compose window open, and try to open another one (whether by clicking “reply” or “new message”), the new window will open, but the old one will disappear, with its content dumped into the drafts folder.
I get this effect on two different Macs (M1 MacBook Air and 27" iMac 5K) on different versions of MacOS, so it seems to be down to the Mail version - Mail 14.0 (3654.100.0.2.22) in both cases. Oddly, someone I know running the same Mail version happily runs multiple compose windows simultaneously!