To make an existing alias your primary alias in Microsoft 365, you need to follow these steps:
- Log into the Microsoft 365 admin center.
- Go to the Users > Active users page.
- Select the user whose aliases you want to manage.
- Under Aliases, select Manage username and email. Note that you won't see this option if the user doesn't have a license assigned.
- On the Manage username and email page, find the alias you want to make primary.
- Select the alias and choose Set as primary.
- Save your changes.
After making this change, it may take up to 24 hours for the new primary alias to take effect. If you encounter any issues, ensure that you have the necessary permissions to make these changes or contact your administrator for assistance.