Adding a custom domain to Office365 using WAAD

I’m playing with my Office 365 Plan E3 Technical Preview subscription for a quite a while now, and I think it’s just great! In this post, I want to guide you through the process of adding a custom domain to your subscription. The way I will show it is by using the Windows Azure Active Directory portal, which I will explain right away.


Did you know that when subscribe to an Office 365 Plan, Microsoft automatically creates a new Windows Azure Active Directory (WAAD) that is associated with your Office 365 account? Well, at first, I didn’t! This is really great! For the people that do not know WAAD, let me quote:

Windows Azure Active Directory (Windows Azure AD) is a modern, REST-based service that provides identity management and access control capabilities for your cloud applications. Windows Azure Active Directory provides a cloud-based identity provider that easily integrates with your on-premises AD deployments and full support of third party identity providers.

When you login at using your Office 365 administration credentials, you see that it’s linked to your subscription like:


Activate your custom domain

Alright, that being said, let’s move on and add a custom domain to our subscription. By default, your subscription domain will be something like That’s great, but using your personal domain is a much more professional way of working of course.  Let’s do that now.

First, click on the ‘domains’ link on the left side. You will see that the  * is already listed there by default. Click on the ‘Add a domain’ button.


In general, the process consists out of 2 mayor steps. First you need to ‘activate’ your domain, meaning that you need to prove that you actually own it. Secondly, you need to ‘manage your DNS settings’ to manage the correct usage of the Office 365 settings. The first wizard you see is the ‘activation’ part. Enter your domain and click ‘next


Now you need to verify that you are the owner of the domain. Out of the box, there are some pre-defined domain registrars listed. My domain is registered somewhere in the Netherlands, so no one of the listed option, so I selected ‘General Instructions


On the next screen, I used the TXT record option. On the DNS management page of my domain registrar, I added the TXT record like:


If you click ‘next’, the service will check the TXT record and you will be able you continue the process. In my case, it only took a few seconds for the TXT record to be applied. In other cases, it can take bit longer. The next step is to select the domain services. In other words, which services will be used with your domain? I selected ‘Exchange’ and ‘Lync’.

Don’t select SharePoint, because the DNS record that you create to enable SharePoint Online for this domain by default restricts all other DNS records from working. What you can do is create a CNAME record with the WWW prefix, and point it to Or even better,, so it will link to the public website. You can then create another CNAME record with the PORTAL prefix, and point it to the SharePoint sites root.


That’s it, your domain is ready to be used, meaning that it’s added to your WAAD account (and thus can be used with your Office 365 subscription).


Configure your custom domain

Now that our domain is active, we can start using it. Click on the ‘Finish’ button (or if you already closed the previous wizard, just click on your Domain and click ‘DNS Settings’.) You will see a nice overview of the DNS entries you need to make on the DNS settings page of your domain registrar. For example:


On the wizard screen, you don’t have the option to ‘validate’ if you entered the correct DNS entries, but there’s an option to validate. Just go back to the screen where you see your domain name listed, click on the domain and select the ‘Troubleshoot domain’ button. It will ask you when you changed the DNS entries. For this quick check, just select ‘more than 72 hours ago’ so it will check it right away. In my case, this was a green result for Exchange (I didn’t configure Lync):


That’s it. Now we can use our custom domain with our Office 365 subscription. Let’s take Exchange for example. To be able to send an email to ‘’, you will need to add the email (alias) to the list of email addresses of the person ‘’. Go to the Exchange admin center – Recipients and edit the mailbox you want. On this new popup, select the ‘email address’ section, and add an SMTP alias like:


That should do the trick, you can now send an email to ‘’, and it should arrive in the mailbox of the user you just configured.

Have fun!

Written by
Alexander Vanwynsberghe
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Alexander Vanwynsberghe

Belgium-based entrepreneur. Into technology, innovation and a bit of cycling and running too. Evangelist for everything related to smart-tech.