If the MSN email address was removed as an alias from the Microsoft account, it is permanently deleted and cannot be restored or added back.
When an alias from a Microsoft-owned domain such as @msn.com, @hotmail.com, @live.com, or @outlook.com is removed from an account, that alias is permanently deleted and cannot be associated with any Microsoft account again. This also means new mail will no longer be delivered to that address.
If the account itself had been completely closed (not just the alias removed), recovery would only be possible within a limited time window, but the provided context clarifies that removing an alias is final.
There is no supported way to get the deleted MSN email address or its mailbox back once it has been removed as an alias.
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