Managing personal Outlook.com account settings, security, and privacy
Hello, thank you for reaching out to Microsoft Q&A.
The error message "This account does not exist" appears if,
- Your account has been deleted due to inactivity - If you haven't signed in with your Microsoft account for more than 2 years, your account will be put into an inactive state and will be closed.
So, may I please know when the last time you were able to sign in with your Microsoft account Successfully?
Another reason,
- Your account may have been compromised - If you have signed in recently with this account and you get this error, it's possible that your account may have been taken over by hackers and might have deleted/removed your email address (Alias) from your account and replaced it with their own address.
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For security reasons, Microsoft no longer allows users to recreate an email address that has already been created. Even if the account has been deleted, the email address cannot be created again.