Remove or Change a user's email alias in Office 365

In Office 365, changing a user's email alias has traditionally been a straightforward process that many engineers have been familiar with. However, due to recent updates by Microsoft, there have been some changes in the way we need to approach this task, causing confusion among a few of my colleagues who reached out to me for assistance. In this guide, I will outline the updated procedure for changing a user's email alias in Office 365, particularly when dealing with a Hybrid setup and synchronization between on-premises Active Directory and the cloud environment.

Change a user's email alias 

Procedure:

1. Open the Azure Active Directory portal by logging in to your Office 365 account.

2. Navigate to the "Users" section.

3. Locate and select the user whose email alias needs to be changed.

4. Open the user's profile and proceed to edit their properties.

Modifying the Email Alias:

1. In the user's properties, look for the "User Principal Name" and "Mail Nickname" attributes. These are the attributes that can now be modified from the cloud environment.

2. Update the "User Principal Name" field with the desired alias for the user's email address.

3. Similarly, modify the "Mail Nickname" field to reflect the new alias.

4. Save the changes to update the user's email alias.

Hybrid Setup Considerations:

It's worth noting that in a Hybrid setup, where synchronization occurs between on-premises Active Directory and Office 365, changing the email alias solely from the on-premises environment (proxy address) may not result in the desired changes. Therefore, it is crucial to utilize the Azure Active Directory portal to modify the necessary attributes mentioned above.

Remove a user's email alias 

In a Hybrid setup, when migrating from a domain removal scenario to an Onmicrosoft domain, there are specific steps that need to be followed to ensure a smooth transition. This guide outlines the necessary procedures, particularly when dealing with licensed and unlicensed users, and the synchronization of attribute changes from the on-premises Active Directory to Azure Active Directory.

Procedure:

Handling Licensed Users:

a. For licensed users, initiate the domain change from the on-premises Active Directory.

b. Make the necessary changes to the user's attributes, including the domain information.

c. Run an Azure AD delta sync to synchronize the exchange attributes to Azure Active Directory.

d. Note that the delta sync will only sync attribute changes to Azure if the user has an active license.

Unlicensed Users:

a. In the case of unlicensed users, a delta sync alone will not sync any attribute changes to Azure Active Directory.

b. Instead, the initial sync command must be used to ensure that the changes take effect.

c. Execute the initial sync command to synchronize the attribute changes for unlicensed users.

When migrating from a domain removal scenario to an Onmicrosoft domain in a Hybrid setup, it is crucial to follow the proper steps for both licensed and unlicensed users. For licensed users, changing the domain from the on-premises Active Directory and running an Azure AD delta sync will effectively sync the exchange attribute changes to Azure. However, for unlicensed users, the delta sync will not suffice, and the initial sync command must be utilized to ensure that the changes take effect. By adhering to these procedures, you can successfully migrate from domain removal to an Onmicrosoft domain in your Hybrid setup.