Forum Discussion
Add another Domain to our Office 365 tenant
Hello all,
We have a tenant which is abc.com recently we bought a new company and we want to add their domain def.com into our tenant abc.com so we can assign license E1 and E3 for the users on domain def.com.
Does this configuration will work without interfering with our actual email from our tenant (abc.com)?
Can you provide step-by-step to do so?
At the end we want users from def.com to be part of our tenant abc.com for us it will be much easier to manage with only one tenant!
Thank you for your precious collaboration!
Best regards,
Hi SilverStar
For your main concern - adding in def.com and pointing the MX records to your 365 tenant will not have any impact to your abc.com domain - it is entirely separate. Your existing users can have a def.com alias if you wish, but it will not change their primary smtp/upn.
You need to ensure you have a plan for the email migration for def.com into your O365 tenant. What is servicing the email at the moment - hosted email, Gmail, Exchange on prem etc - and how will you migrate users to the new domain? Are there on-prem Active Directories?
Hi SilverStar
Provided you own the domain, you can add additional domains to your M365 tenant without interrupting existing domains.
The above shows you how. One thing to note is that if def.com is already set up as a domain in another M365 tenant, then it must be removed before you can add it to yours.
Good morning HidMov...
Thank you I already consult this article from Microsoft...you know my main concern if I add the domain def.com will I be able to add DNS records (MX records) so the newly domain can send and received email without causing any issue for our main domain which is abc.com
Domain def.com are not in Microsoft 365 yet...this is why I am asking the question to incorporate this domain into our existing tenant some people say this:
- No it is not as easy as adding an SMTP domain and you have a couple options available
- Full maintenance of separate tenants
- A migration of one tenant to another and set up a “send as” group email rule
You can add the SMTP and receive emails for domain 2 , but NOT send as
Best regards HidMov and have a nice day!
Hi SilverStar
For your main concern - adding in def.com and pointing the MX records to your 365 tenant will not have any impact to your abc.com domain - it is entirely separate. Your existing users can have a def.com alias if you wish, but it will not change their primary smtp/upn.
You need to ensure you have a plan for the email migration for def.com into your O365 tenant. What is servicing the email at the moment - hosted email, Gmail, Exchange on prem etc - and how will you migrate users to the new domain? Are there on-prem Active Directories?
