Configuring a Custom Domain Name in Microsoft 365

When you first sign up for a Microsoft 365 tenant, you will be assigned a domain name in this format: name.onmicrosoft.com. The name part of the domain can be patterned after the company name, such as constoso.onmicrosoft.com, or a random one, like 8fv9yn.onmicrosoft.com.

If your tenant will be used for development or testing only, the default domain might be sufficient. Otherwise, you definitely will want to use a custom domain name for your organization. So if you’re asking, “How can I have an Office 365 email address with my own domain name?” then you’re in luck.

This article will guide you through the steps of configuring a custom domain in Microsoft 365. We’ll look at adding a new domain, verifying the ownership, and using the new domain in usernames and email addresses.

Step 1: Getting a Custom Domain Name

But first, a domain name. If you don’t have one yet, you will need to purchase it from various domain registrars. Some of the well-known domain registrars are Namecheap, VeriSign, DigiCert, Bluehost, and GoDaddy, among others.

The procedure of obtaining the domain name varies depending on the registrar you choose, and so does the price.

Step 2: Adding the New Domain Name in your Microsoft 365 Tenant

Assuming you’ve already purchased the custom domain name, let’s continue to add it to your Microsoft 365 tenant.

1. Log in to the Microsoft 365 Admin Center at https://admin.microsoft.com.
2. Navigate to Settings > Domains and click Add Domain.
   
3. In the Add domain step, type the domain name you wish to add and click Use this domain.
   

Step 3: Verifying the Domain Ownership

Microsoft 365 automatically detects your domain host. This process supports many domain hosts where the verification process is automated. In this example, the domain host is Cloudflare.

1. To continue, click Verify.
   
2. Sign in to your domain host.
3. Click Authorize to authorize Microsoft to create the TXT record for domain verification.
   

Step 4: Adding Required DNS Records

Microsoft offers to automatically manage your DNS records if it supports it. In this example, Cloudflare is supported, and we can choose to let Microsoft add the required DNS records.

But for demonstration, let’s get our hands dirty and add our own DNS records.

1. Select Add your own DNS records and click Continue.
   You’re given a list of DNS records to add to your DNS host.
   
2. Now, open your DNS host and add the required DNS records. Again, the process will be different depending on which domain host you have. The screenshot below shows the DNS records added in Cloudflare.
   
3. Once you’ve added the DNS records, wait for at least 10 minutes to allow for propagation. After which, go back to the Microsoft 365 Admin Center and click Continue.
   
   Note. Some DNS propagation could take hours. So you may need to repeat this step several times.
   Microsoft will now check those DNS records.
   
4. And if everything goes well, you’ll get a confirmation message, as shown below. Click Done.
   The custom domain name is now added to your tenant.
   

Step 4: Modifying Usernames and Email Addresses

Your custom domain is now set up. That means you can now use it for the user domain name and email address. But that doesn’t happen automatically, so let’s do it.

Single User

You can change the user domain name and email address of a single user using these steps.

1. Navigate to Users > Active users and click the user to edit.
   
2. Next, click the Manage username and email link.
   
3. Type the username, select the custom domain name from the dropdown, and click Add.
   
4. If you’re only adding an alias email address, click Save changes now.
5. But if you want to make the new alias the primary email address and username, click the ellipsis next to the new alias and click Change to primary email.
   And you’ll see that the new alias is now the primary email address and username. Click Save changes.
   

Multiple Users

If you want to apply the new custom domain name to multiple users, follow these instructions.

Note. Changing the domain of bulk users will automatically change their usernames and primary email addresses. There is no option to just add an email alias only.

1. Select multiple users from the Active users list and click the Change domains button.
   
2. Choose the new custom domain name from the dropdown and click Save changes.
   
3. Wait for the changes to be saved. How long it takes depends on how many users you select.
   
4. When the process is done, you’ll get a confirmation message, as shown below.
   

You’ve now completed adding a custom domain name to your Microsoft 365 tenant.

Conclusion

Configuring a custom domain name in Microsoft 365 can be a simple process as long as you follow the necessary steps and ensure that your DNS records are set up correctly. By using your own domain name, you can enhance your brand identity and make it easier for your customers and partners to find you online.

Whether you are using Microsoft 365 for email, SharePoint, or other applications, having a custom domain name can provide a more professional appearance and improve your online presence. With the help of this guide, you should be able to set up your own custom domain name in Microsoft 365 with ease.