I am unable to actually change any settings for any of these email windows before a new window pops up. I think it is trying to open somewhere between 150-200 windows.
iCloud+ settings seem fine. Mail is working just fine on my Mac Mini and iPhone.
I’ve tried reinstalling (impossible, actually), rebooting, force quitting about 50 times now, holding down Shift when opening Mail, and even deleting some mbox messages in Library. So far none of these things makes any difference.
I haven’t found anyone else having this same issue in any Google searches.
wouldn’t I have to be able to first see and then select a mailbox first? I never get a chance. Menu and mailboxes are completely unresponsive while windows are spawning. They are spawning fast, one or two per second…
EDIT: I managed to open the Mailbox menu, but Rebuild was greyed out. Tried hitting different inbox locations on left under Favorites and iCloud - nothing changed in menu. Then windows covered that all up again.