Additional MX record on Microsoft DNS

Copper Contributor

Hi All,


Hoping someone can help me on this

Our exchange server is on O365

We have subscribed to a cloud Spam filter third party service, so I was trying (as per the recommendation of the Spam filter vendor) to add an second MX record with lower priority to  DNS to start with. Our Nameservers are all on

When trying to add the mx record I get the following message

" Adding additional MX records is not allowed when using Exchange email service. To continue adding your custom MX record, you will need to disable first the exchange service from being used by this domain. If your're this record during setup, go back to the previous wizard page, otherwise use the DNS management button details page and reconfigure the services used by your domain."


How do I resolve this!


Thanks in advance


3 Replies

Hi @aghattasnationstranslationcom,


You just have to follow the instructions provided in the error, this will not disable the Exchange Service. this will only unlink the service from being mapped directly from the Microsoft online DNS.

Then you can add your custom MX records, but before that I'll suggest to backup the current settings like mx, cname (Autodiscover), txt (SPF), dmarc and dkim, in case there will be removed automatically.


You might want to test this system with a test domain first, before routing all your traffic.


Hope this will be of any assistance to you,


hi michael, i am facing the same issue, where can i find a step by step guide to do this, without doing anything wrong?


thx in adv.



Yes the above concern perfectly working. I have uncheck exchange online services and added MX record manually with the high priority and additionally added 3rd party mx record with the priority of low. 


We have checked the mail flow and its working perfectly. Based on that the mail flow happened between both inbound and outbound.


Thanks in advance.