My wife is a keen Apple products user and has now purchased a MacBook Air. After a recent OS upgrade to ‘Sierra’ (v10.12) she couldn’t log into her Hotmail (Outlook) account as it wouldn’t accept her perfectly valid password. The error message stated “Mail account already exists”.
The solution is fairly straightforward
- Click the Apple logo (top right) and select System Preferences
- Select iCloud
- Sign out of iCloud
- Log in to Hotmail email account on MacBook
- Sign in to iCloud
Both email and iCloud should now work.