Add a domain to Microsoft 365 Step by Step

Reading Time: 6 minutes

In this blog post I will add and verify a domain in the Microsoft 365 admin portal. I will also setup an email address using the newly added domain via the Exchange admin center. Finally, I will test to ensure I can send and receive emails.

  1. Login to the Microsoft 365 Admin Portal at (Login with Global Admin account)
  2. Click Show All

    Note: you could also add the domain by clicking Setup.

3. Click Settings

4. Click Domains

5. As you can see from the below screenshot, I have my default domain displayed

6. Click Add Domain or purchase a new one by clicking Buy domain

7. Add a domain if you already own one and click use this domain when ready

8. I’ll be selecting the option to add a TXT record to my external domain DNS portal. Click continue

9. Microsoft provide a TXT record which I will need to add to my domain DNS portal. This process verifies that you own the domain you are trying to add to 365

10. I login to my domain portal at my domain registrars website, locate DNS and click to add a new TXT record.

11. I add the details and click Add Record

12. TXT record added successfully

13. Back to the 365 portal to verify the domain. If the domain does not verify, allow time for replication

14. The following appears after Microsoft have verified your domain. You may want to stop at this point as you may not want to configure email routing just yet without planning. I’ll explain further at step 15 below.

The text states:

Connect your domain to your Microsoft services so you can use email and instant messaging. There are a couple of options to consider, depending on how you’d like to manage domain name service (DNS) records for your domain ‎‎.

Add your own DNS records. We’ll provide a list of DNS records that you’ll need to add for your domain at your DNS host.

15. If you decide to cancel the setup after verification, you’ll find that the new domain is now available within Exchange Admin Center. Let’s take a look. Note that your domain has been verified so if you decide to cancel the wizard at this point. You can return and continue from where you left at a later time. Let’s login to Exchange Online and check the status of the new domain aswell as add a new email alias to my mailbox. No email routing has been configured at this point.

– Access Exchange Admin Center

– Click Mail flow

– Click accepted domains and you’ll find that the domain has been added as your default domain

-I won’t be able to receive email to this domain until I continue with configuring the required DNS/MX records but I am in a position to start configuring email addresses.

– Click on recipients

-In the example below, my mailbox is still set to the default address

– Click the edit icon or double click the name

– Click email addresses, add your email address and save

– My email address has changed from the default to my newly added domain.

16. I want to continue with setting up my records to allow me to send and receive emails to my new email address

You can continue with the domain setup at anytime. Note that if you’re using an external email filtering solution such as Mimecast the process is different so some planning is required before you decide to make this serious change of routing email into O365. Routing email changes should be completed at a suitable time to reduce impact to your users.

So i have acccessed the Microsoft 365 Portal, clicked settings, domains and clicked my domain which is currently displaying a status of Incomplete setup

17. Click Continue Setup

18. And we’re back at the setup screen we left earlier

19. Click more options and the below options appear

20. I will be selecting the default option Add your own DNS records, click continue

21. Microsoft have provided me with further records to add to my domain portal for

You’ll find a further option towards the bottom of the page as shown below. If you decide to click the options below, further DNS records will be provided for Skype For Business and Intune and Mobility Device Management for Micrsosoft 365

22. For the purpose of this demo, I will only be working with Exchange Online. Let’s add the MX, CNAME and TXT records to my domain portal for before we continue. Back to my domain portal to add the records.

23. Records added as specified by Microsoft, back to the portal.

Note: It may take some time for changes to replicate but in most cases the process does not take long. You will want to plan the replication time into your schedule as in some cases it can take up to 24 hours for DNS records to replicate.

24. Click continue

If there are issues, Microsoft will assist by providing recommendations on how to resolve your issues, for example, if you have typed or copied a record incorrectly, Microsoft will raise this on the next page.

25. Success, domain setup completed. I should now be able to send and receive emails.

26. Earlier in this blog post I assigned an email address to my mailbox via the Exchange Admin Center, so let’s test by logging into my mailbox and test email.

Send email outbound from

Email received

Let’s reply to the email

Email received successfully

Stay tuned for further blog posts

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