Unable to create MX record

Question

Hi

I recently signed up for a M365 E3 subscription.
In M365 admin center under Domains, I can only see 1 domain ending with onmicrosoft.com.

When I selected Add record inside this domain, I can only see TXT (Text) but not MX record.

I am trying to set up a multifunction device to send email using Microsoft 365 or Office 365 and according to following microsoft document under option 3, I need to create an MX record which I can't.

https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/how-to-set-up-a-multifunction-device-or-application-to-send-email-using-microsoft-365-or-office-365

Appreciate your advice what went wrong. Thanks.

Regards

Ben

Answer 1

You can't add MX records for .onmicrosoft.com domains. These are managed by Microsoft and by default their MX record points to the Exchange online service and you cannot change this.

If you want to add your own custom domain then you first must verify that you own this domain. Otherwise, you could just add an MX record for any domain you want which could create conflicts with existing MX records belonging to other organisations.

The verification process is performed by first creating a TXT record. This allows Microsoft to verify that you have access to the DNS zone and can create DNS records. Once the TXT record is verified then you can create MX records. The verification process is quite quick to perform.

More details here: https://learn.microsoft.com/en-us/microsoft-365/admin/setup/add-domain?view=o365-worldwide

Answer 2

Answer 3

Hi Alan

Do I need to create a connector in Exchange Admin Center. Currently there are no connectors.

Step-by-step configuration instructions for SMTP relay

1. Obtain the public (static) IP address that the device or application with send from. A dynamic IP address isn't supported or allowed. You can share your static IP address with other devices and users, but don't share the IP address with anyone outside of your company. Make a note of this IP address for later.
2. Sign in to the Microsoft 365 admin center.
3. Go to Settings > Domains, select your domain (for example, contoso.com), and find the MX record.

The MX record will have data for Points to address or value that looks similar to contoso-com.mail.protection.outlook.com.

4. Make a note of data of Points to address or value for the MX record, which we refer to as your MX endpoint.
5. Check that the domains that the application or device will send to have been verified. If the domain is not verified, emails could be lost, and you won't be able to track them with the Exchange Online message trace tool.
6. In Microsoft 365 or Office 365, select Admin and then Exchange to go to the new Exchange admin center.
7. In the Exchange admin center (EAC), go to Mail flow > Connectors. The Connectors screen is depicted in the subsequent two images below, for New EAC and Classic EAC, respectively.
8. Check the list of connectors set up for your organization. If there is no connector listed from your organization's email server to Microsoft 365 or Office 365, create a connector in the Exchange admin center (EAC):

Classic EAC:

Open the EAC at https://admin.protection.outlook.com/ecp/ and go to Mail flow > Connectors, and then click Add Add icon.. In the wizard that opens, choose the options that are depicted in the following screenshot on the first screen:

Choose from your organization's email server to Microsoft 365 or Office 365.

Click Next, and give the connector a name.

On the next screen, choose By verifying that the IP address of the sending server matches one of these IP addresses that belong to your organization, and add the IP address from Step 1.

Leave all the other fields with their default values, and select Save.

New EAC:

Open the EAC at https://admin.protection.outlook.com/ecp/ and go to Mail flow > Connectors. Or, to go directly to the Connectors page, use https://admin.exchange.microsoft.com/#/connectors.

Click Add a connector Add a connector icon.. In the wizard that opens, choose the options that are depicted in the following screenshot on the first screen:

The screen on which you configure the sending server as your organization server and the destination server as Microsoft 365 server.

Click Next. The Connector name screen appears.

Provide a name for the connector and click Next. The Authenticating sent email screen appears.

Choose By verifying that the IP address of the sending server matches one of these IP addresses which belong exclusively to your organization, and add the IP address from Step 1 of Step-by-step configuration instructions for SMTP relay section.

Click Save.

1. Now that you're done with configuring your Microsoft 365 or Office 365 settings, go to your domain registrar's website to update your DNS records. Edit your SPF record. Include the IP address that you noted in step 1. The finished string should look similar to this v=spf1 ip4:10.5.3.2 include:spf.protection.outlook.com ~all, where 10.5.3.2 is your public IP address. Skipping this step can cause email to be sent to recipient Junk Email folders.
2. Now, go back to the device, and in the settings, find the entry for Server or Smart Host, and enter the MX record POINTS TO ADDRESS value that you recorded in step 3.
3. To test the configuration, send a test email from your device or application, and confirm that it was received by the recipient.

Regards

Ben