Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi, @Thierens Cedric
Are the backup accounts also Outlook, Hotmail, or Live accounts? If so, open a separate InPrivate window for each backup account. This prevents the browser from signing you out of the original account while you retrieve the code.
Also, what exact message appears when you try to sign in to the backup accounts? Are the security codes arriving, or are you unable to open the accounts to read them?
Please avoid requesting codes repeatedly, as too many attempts can cause a temporary security block. You can also run Microsoft’s account Sign-in Helper to check the affected account.