After migration Mail does not work
I migrated from an older Mac to a newer one compatible with Big Sur. After migration, when starting Mail, I get the dialog to set up the account . I select iCloud. After entering my icloud account name etc, I get the list of which parts of iCloud i wish to set up (all of it of course), after clicking the button to proceed, I can see that the button indicates being depressed by a colour change, but then nothing happens. I can appreciate it may take some time, but the dialog does not disappear, no spinning beach balls etc. The only thing I can do is to 'force quit' mail. What is going on here?
iMac Line (2012 and Later)