Nowadays many small businesses synchronize their user accounts and passwords to Office 365 using Azure Active Directory Connect. When an administrator wanted to make changes to the email address, add or remove aliases on an Office 365 mailbox, you’ll get an error similar to this:
This error is caused by the Source of Authority or the identity reference is located in the on-premise Active Directory not in the Azure Active Directory. If the business have a hybrid Exchange environment, then changing the email attributes will be done in the on-premise Exchange server. However, businesses that don’t have on-premise Exchange server, will still be able to edit the email address via Active Directory Users and Computers snap-in.
Here are the steps,
- Launch Active Directory Users and Computers on your Domain Controller
- Verify “Advanced Features” is enabled from the view menu
- Double click on the user account that you would like to edit the email address, alias, etc.
- Select “Attribute Editor” tab
- Scroll down until you see “proxyAddresses” attribute and then click Edit
- In here you can edit the email address or alias. The primary email address must be in uppercase “SMTP” and alias in lower case