Using older versions of Outlook for Mac for personal email and calendar
Hi William,
I'm Cherrelyn, and I’m here to help.
If your wife's Hotmail address was recently deleted due to alias changes, and you're now getting a message that the address is part of a reserved domain, it's likely still in Microsoft's system under a grace period and hasn't been released for reuse yet. Unfortunately, reserved domain emails (like Hotmail.com) are often protected and cannot be re-registered, even by the original user, after deletion especially if they're flagged as legacy or reserved. Since this occurred less than a week ago, I recommend to signing in with the original account credentials at Outlook.com to see if the account is still recoverable. If that fails, try the account recovery form, using any recent information to validate ownership. If recovery fails again, it’s best to contact Microsoft Support directly and explain that the deletion was accidental and very recent. They may still be able to help restore the account or email alias from the back end if it's within the retention window.
I hope this will help and if you have any question please don't hesitate to reply to this thread.
Warm regards,
Cherrelyn