Adding a domain to Microsoft 365
How to connect your business domain to Microsoft 365 so your team can use professional email addresses like you@yourcompany.com instead of @outlook.com.
When you first set up Microsoft 365, your email addresses use Microsoft's default domain: something like name@yourcompany.onmicrosoft.com. To use a professional address like you@yourcompany.com, you need to connect your domain to Microsoft 365.
What you'll need
- The Domain Name Administrator role in the Microsoft 365 admin center. Microsoft is strict about this one: because adding a domain affects the whole organization, regular users and limited custom admin roles can't do it.
- Access to your domain registrar (where you registered your domain, for example, GoDaddy, Namecheap, Cloudflare)
- Your domain name (for example,
yourcompany.com)
If you're not sure who your domain registrar is, see How to find where your domain is registered.
Check whether your registrar supports Domain Connect
Microsoft recommends a route called Domain Connect. With a registrar that supports it, you sign in at the registrar once and Microsoft confirms ownership and writes the DNS records itself, no copying record values around. Microsoft's own list of Domain Connect registrars includes GoDaddy, Aruba, IONOS, EuroDNS, Cloudflare, WordPress.com and Plesk. If your registrar isn't supported, you do the same steps manually.
Add your people before you switch the email records
Microsoft's guidance is to create the user accounts and mailboxes for everyone who gets email on the domain after you add the domain but before the MX record changes. That way nobody's mail lands at Microsoft with no mailbox waiting for it.
Adding the domain
Sign in to the admin center at admin.microsoft.com.
Select … Show all in the left navigation, then Settings → Domains. (Domains is one of the items hidden until you expand the menu.)
Select + Add domain.
Enter your domain name (for example, yourcompany.com) and select Use this domain.
Verify you own the domain. What the Verify you own your domain page asks for depends on your registrar.
- With Domain Connect: check that the registrar Microsoft has detected is the right one (if it isn't, select choose a different domain host) then select Verify. A window from your registrar opens. Sign in there and authorize Microsoft to add the verification TXT record. Turn pop-up blockers off first, or that window never appears.
- Without Domain Connect: Microsoft offers you a choice of proofs, a TXT record, an MX record, or a text file uploaded to your website. Pick one and select Continue, add the record or file at your registrar, then come back and select Verify.
Choose how to connect the domain. On the How do you want to connect your domain page, select Continue. To add the DNS records yourself instead, select More options → Add your own DNS records → Continue.
Add the DNS records. On the Add DNS records page, tick the Microsoft 365 services you want records for, and expand Advanced options to see the rest. Typical records are:
- MX record: tells the internet to deliver email to Microsoft
- CNAME records: for services like Autodiscover (auto-configures email apps)
- TXT record: for SPF (helps prevent your emails being marked as spam)
With Domain Connect, select Add DNS records and authorize them in the registrar window that opens. Otherwise, add them by hand at your registrar and then select Continue. See DNS records explained if you need help.
Finish. When the Domain setup is complete page appears, select Done.
Verification and DNS changes are not instant
Microsoft says verifying ownership can take up to about ten minutes after you add the record, and that some registrars need longer, up to 48 hours. Your website keeps working where it is; Microsoft says the Domain Connect setup steps don't affect it.
Email may be disrupted during the changeover
When your MX record changes, there is a period where email could be delayed while the old record ages out of the internet's caches. How long that takes depends on the TTL your registrar had set on the record. Tell your team about the planned change window.
Four hops, all of them in milliseconds. The resolver is the one that remembers, which is why a record you changed this morning can still be invisible to some visitors this afternoon, until its TTL expires.
Read this as text
When somebody types your domain, their browser does not know where your site is. It asks a DNS resolver, run by their internet provider, or by a service like Cloudflare or Google.
If the resolver does not already know the answer, it asks your domain’s authoritative nameservers, which hold the official records for your domain. They reply with the IP address, for example 185.199.108.153.
The browser then connects straight to that address and your site loads. The nameservers are not involved again.
The resolver keeps that answer for a set period, the TTL. Until it expires, that resolver keeps handing out the old answer without asking your nameservers again, which is the whole reason a DNS change can take minutes for one person and hours for another.
If you verify with an MX record, set the priority high
Microsoft offers an MX record as an alternative proof of ownership when you can't add a TXT record. If you use it, give that record a high priority number so it doesn't start pulling mail away from your current email provider before you're ready.
After adding the domain
- Update existing user email addressesGo to Users → Active users, select the person, and on the Account tab select Manage username and email to move them from
@onmicrosoft.comto@yourcompany.com. - Set your domain as the defaultIn Settings → Domains, select the domain and choose Set as default. Note that this only affects accounts created from then on; it doesn't rewrite anyone's existing address.
- Add SPF, DKIM, and DMARC records for better email deliverability. Microsoft will prompt you to do this, or you can read Email DNS records explained for guidance.
Granting us access to help
If you'd like Chykalophia to help with the domain connection, grant us admin access to your Microsoft 365 account and access to your domain registrar. Our default account is support@chykalophia.com unless your project lead has given you a different address.
Common questions
Can I have more than one domain on Microsoft 365?
Yes, you can add multiple domains (for example, yourcompany.com and yourcompany.co.uk) and assign email addresses to users from any of those domains. Microsoft puts the typical ceiling at around 5,000 domains, so no small business is going to run out. Follow the same process for each additional domain.
What if I already have email hosted somewhere else?
When you add your domain and update the MX records, email will start flowing to Microsoft 365. Your old emails won't automatically migrate. You'll need to export them from the old provider and import them into Microsoft 365. We can help with this migration.
What is the onmicrosoft.com domain for?
The yourcompany.onmicrosoft.com domain is Microsoft's fallback domain for your organization. Microsoft creates it when you sign up and uses it behind the scenes for your subscription, so it can't be removed. You don't have to use it once your own domain is connected, but it keeps working for email if you want it. You can create a different onmicrosoft.com name and make that the fallback, though you can't rename or delete the original, and you're limited to five of them.
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