'%3e%3cpath%20d='M8%200C12.4183%200%2016%203.58172%2016%208C16%2012.4183%2012.4183%2016%208%2016C3.58172%2016%200%2012.4183%200%208C0%203.58172%203.58172%200%208%200ZM11.6162%204.38379C11.2257%203.99337%2010.5927%203.99338%2010.2021%204.38379L8%206.58594L5.79785%204.38379C5.40732%203.99334%204.77429%203.99329%204.38379%204.38379C3.99331%204.77429%203.99335%205.40733%204.38379%205.79785L6.58594%208L4.38379%2010.2021C3.99348%2010.5927%203.99341%2011.2257%204.38379%2011.6162C4.77426%2012.0066%205.40734%2012.0065%205.79785%2011.6162L8%209.41406L10.2021%2011.6162C10.5927%2012.0066%2011.2257%2012.0067%2011.6162%2011.6162C12.0067%2011.2257%2012.0066%2010.5927%2011.6162%2010.2021L9.41406%208L11.6162%205.79785C12.0066%205.40735%2012.0066%204.77429%2011.6162%204.38379Z'%20fill='%23080E17'%20fill-opacity='0.46'/%3e%3c/g%3e%3cdefs%3e%3cclipPath%20id='clip0_3761_713'%3e%3crect%20width='16'%20height='16'%20fill='white'/%3e%3c/clipPath%3e%3c/defs%3e%3c/svg%3e)
Why Your Microsoft 365 onmicrosoft.com Alias Doesn't Change After a Name Update
Question details
The user wants to know why the original onmicrosoft.com email alias remains unchanged after updating a Microsoft 365 user's name, and whether the address can be renamed.
- Product
- Microsoft 365
- Device & OS
- not provided
- Scenario
- Updating a user's name and primary email address in the Microsoft 365 admin center.
- Observed behavior
- The primary email address updates successfully, but the original username@company.onmicrosoft.com address remains as an alias and does not automatically update to reflect the new name.
Verify that the user's primary email address has been successfully updated and confirm that they can currently send and receive emails without any mail flow issues.
Understand Microsoft 365 Default Alias Behavior
Recognize that the persistence of the original onmicrosoft.com alias is expected system behavior and does not negatively impact normal email delivery.
When you change a user's name in Microsoft 365, the primary email address updates automatically. However, the system intentionally retains the original onmicrosoft.com address as a secondary alias.
This mechanism ensures that any internal routing, backend processes, or historical dependencies linked to the original tenant domain remain intact. Since the user can still send and receive mail normally via their new primary address, no troubleshooting or renaming is technically required.
Confirm with the user that they can send and receive emails using their new custom domain primary email address.
Navigate to the Microsoft 365 admin center, select 'Users', click on the specific user, and verify under 'Manage email aliases' that the old onmicrosoft.com address is safely listed as a secondary alias.
Add a New onmicrosoft.com Domain
If you require a completely different onmicrosoft.com domain address for branding or routing purposes, you must add a new domain to your tenant.
Manage Your Documents Effectively with WPS Office
While Microsoft 365 handles your complex email domains and backend administrative routing, you might prefer a lightweight, fast, and free office suite for your daily document creation. WPS Office provides excellent offline capabilities without the complex administrative overhead.
- 1. Download the software: Visit the official WPS Office website and download the free installation package for your operating system.
- 2. Install and open: Run the installer and open WPS Office to immediately access Writer, Spreadsheets, and Presentation modules.
- 3. Edit Office files: Open your existing .docx, .xlsx, or .pptx files directly in WPS Office to view and edit them with perfect formatting.
Frequently Asked Questions
Does keeping the old onmicrosoft.com alias affect mail flow?
No, retaining the old alias does not affect mail flow. The user will continue to seamlessly send and receive emails using their primary custom domain address, while the alias acts quietly as a backend routing mechanism.
Can I completely delete the onmicrosoft.com alias?
It is highly recommended not to remove the default onmicrosoft.com alias. Deleting it without thoroughly verifying its dependencies might break backend processes, SharePoint link access, or internal Microsoft 365 email routing.
Why can't I just edit the username in the onmicrosoft.com alias?
Microsoft 365 permanently ties the original onmicrosoft.com domain routing to the initial account creation. It does not allow direct editing of this specific fallback alias; administrators would need to provision an entirely new onmicrosoft.com domain instead.
