Not sure if this is the right forum. Since installing Big Sur I seem to be having real problems with my Mac Mail. I have around 10 email addresses, mostly company addresses (I freelance). All of them are IMAP configured. I have two Macbooks and an iphone 11. Emails come randomly to the Macbooks; some will arrive on one and not the other, even though the address is the same. All arrive on the iphone, but if I open them there, they then disappear from the Macbooks. The second problem I have is that on one of the Macbooks, there are three in boxes for the same email address; and again, emails arrive in the various boxes randomly. I'm completely baffled but living with it because I don't know if I have the time or patience to rebuild everything! Anyone any ideas? Thanks.