Remove aliases

To stop an unknown email address (alias) from appearing as a contact or sign‑in option on a personal Microsoft/Outlook.com account, remove or restrict that alias in the Microsoft account settings.

Follow these steps:

1. Remove the unknown alias from the Microsoft account
   1. Go to Manage how you sign in to your account: https://go.microsoft.com/fwlink/p/?linkid=842796
   2. Sign in with the correct Microsoft account if prompted.
   3. Under Account aliases or Account username, locate the unknown email address.
   4. Select Remove next to that alias.
   Important notes from the documentation:
   • If the unknown address is from a Microsoft domain (for example @outlook.com, @hotmail.com, @live.com, @msn.com), removing it permanently deletes that alias and it cannot be associated with any Microsoft account again.
   • If it is currently the primary alias, another alias must be set as Make primary before it can be removed.
   • If the unknown address is from a non‑Microsoft domain (for example @gmail.com), once removed it usually becomes immediately available to be added as an alias on another Microsoft account.
2. (Optional) Block that alias from being used to sign in If the address is an alias that should remain for mail delivery but must not be used to sign in:
   1. Go to https://account.microsoft.com and sign in.
   2. Select Your info > Sign-in preferences.
   3. Clear the checkbox for that alias so it cannot be used to sign in.
   4. Select Save.

If the unknown address was added by someone else and there are signs of account compromise, also review security info and verification methods and remove anything not recognized.

References:

• Add or remove an email alias in Outlook.com
• Block an email address from signing in