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Please note that a Microsoft email address (alias) and a security verification method (recovery email address) are different.
Alias – An alias is an alternate email address that you use to sign in to your Microsoft account. It shares the same Outlook email, OneDrive storage, and contact lists as your primary email address.
So, if you remove the Microsoft domain email address on the Manage how you sign in to your account page, please note that you are permanently deleting that email address, and it cannot be associated with any other Microsoft account again.
You also cannot recreate that email address. See,
Add or remove an email alias in Outlook.com
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Security information – This is an alternate security contact method, such as a recovery phone number or email address, used to verify your identity. During sign-in, you may be asked to verify your identity to prove that you are the owner of the account.
If you remove all of your previous security information and replace it with something new, your account will be put into a restricted state for 30 days. Microsoft cannot expedite the 30‑day waiting period.
So, first check whether you removed the alias or the security information from your Microsoft account.