Every five minutes or so a message appears on my wife's MacAir that says
Mail Password Required
If you click on Continue, it takes you to Internet Accounts in settings. There I can see two email accounts, iCloud and Hotmail. It is the hotmail account that has the problem, so she types in her password and then another message appears:
Only one Mail account can be enabled at a time.
Enabling the Mail account "email@example.com" will disable "firstname.lastname@example.org" on this Mac.
If you click OK, the same Mail Password Required comes up again in a few minutes.
Can anyone offer an explanation? Is there some other account setup somewhere? Is there a separate system in Mail, for instance?