How to do a custom domain name without the .onlicrosoft.com

Question

Would like to change my domain name to my original without the onmicrosoft.com

Answer 1

Hi @Russell Shrauner, 

Thank you for reaching out to the Microsoft Q&A forum and for clearly outlining your concern. 

Based on the details you shared, I understand you would like your Microsoft 365 sign in and email addresses to use your original custom domain rather than the default *.onmicrosoft.com domain. I truly understand and appreciate your effort in explaining what you are aiming to achieve. 

Microsoft 365 assigns every tenant a default onmicrosoft.com domain, and this default cannot be renamed or removed. It remains in the background to support service operations. However, once you add and verify your own domain and make it the default, users will sign in and send and receive email using your custom domain. 

To move forward smoothly, please follow the steps below which are tailored to your situation and designed to be easy to follow. If you’re not an admin, kindly share these steps with your IT administrator. 

1/ Add and verify your custom domain 

First, sign in to the Microsoft 365 admin center using a Global admin account. 

• Go to Settings, then Domains, and select Add domain. Enter your domain, for example yourdomain.com. 
• Choose TXT verification, then copy the TXT record shown in the wizard. At your domain registrar, create the TXT record exactly as provided and save the change. 
• Return to the admin center and select Verify. 
• When prompted to add DNS records, choose to add them yourself. Create the required records at your DNS host, including the MX record for Exchange Online mail delivery, the SPF TXT record for sender validation, and the CNAME records such as autodiscover. If you use Teams Phone or other services, add any additional records shown in the wizard. 

2/ Make your custom domain the default for sign in and email 

Next, set your new domain as the default so that new accounts automatically use it. 

• In the Microsoft 365 admin center, open Settings, then Domains, select yourdomain.com, and choose Set as default. 
• In the Exchange admin center, go to Mail flow and then Accepted domains. Ensure yourdomain.com is Authoritative and set as the default email domain. 
• Confirm that new users and groups will be created with addresses in yourdomain.com by default. 

3/ Update existing users to the new domain 

Finally, switch current users so their username and primary email use yourdomain.com. 

• In the Microsoft 365 admin center, go to Users and then Active users. Open a user and select Manage username and email. 
• Change the Username to ******@yourdomain.com and set the primary email address to the same. Keep the previous onmicrosoft.com address as an alias so that any messages sent to it will still arrive. 
• Ask users to sign out and sign back in across all apps and devices. Allow up to 24 to 48 hours for the changes to fully propagate in services such as Teams and SharePoint. 

Additionally, after the switch, you can enhance email security by enabling DKIM in the Exchange admin center and then consider adding a DMARC record once SPF and DKIM are active. 

I hope this information is helpful. Please follow these steps and let me know if it works for you. If you have any updates regarding the issue, please feel free to share them with me.       

Thank you for your patience and your understanding. I look forward to continuing the conversation.

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Answer 2

To change your domain name from the default onmicrosoft.com to your custom domain, you will need to follow these steps:

1. Acquire a Custom Domain: First, ensure you have your own domain name (e.g., yourdomain.com). If you do not have one, you can purchase it from a domain registrar.
2. Add Your Custom Domain to Microsoft 365: In the Microsoft 365 admin center, go to the Settings > Domains page. Here, you can add your custom domain.
3. Verify Your Domain: You will need to verify that you own the domain by adding a TXT record to your DNS settings with your domain provider. This process may take some time to propagate.
4. Change User Email Addresses: Once your custom domain is verified, you can change the email addresses of your users to use the new domain instead of the onmicrosoft.com domain. Make sure to create mailboxes for all users under the new domain before changing the MX records.
5. Set Default Domain: You can set your custom domain as the default for new email addresses in the admin center.

Note that while you can add and use your custom domain, the initial onmicrosoft.com domain cannot be removed or renamed, as it is used behind the scenes for your subscription.

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References:

• Change your Microsoft 365 email address to use your custom domain
• Domains FAQ