Unable to remove a secondary domain

You are unable to delete a secondary domain due to existing email aliases.

• Admin console

You must delete all the alternative email addresses and rename any Google Group that still use the domain name that will be deleted to be able to delete the secondary domain.

1. Go to the Admin console.
2. Click on Directory > Users and click on any of the users.
3. Once you click on the name you should see the user's profile, on the right side you will see User information, click there.
4. Click on the Alternate email addresses (email alias) and remove the alias, then click Save.