What is the hostname of my Office 365 MX records?

In the current article, we will review how to find the value of the “Office 365 MX record” that represents our domain name which we registered with Office 365. After we register our domain name and verify the domain name, Office 365 automatically create a dedicated MX record for each of the public domain that we register.

What is the value of the MX record

To be able to inform the “world” that our mail infrastructure hosted by Office 365 mail services, we will need to add the required MX record in the DNS that hosts our domain name.

The question is – how can we know what the value of this MX record is?

The MX record that is created for our domain name is based on a predefined naming conversation.

The Office 365 MX records consist of two parts:

1. The “static” part

Office 365 uses the same static suffix for all the domain names
hosted at Office 365 – mail.protection.outlook.com

2. The dedicated part

This section is created for a particular public domain name which was registered.

The naming convention based on the following structure.

Organization name, the hyphen characters and the domain name suffix.

To be able to demonstrate this naming structure, let’s use the domain name – o365info.com

In the following diagram, we can see that process in which Office 365 creates a dedicated MX record for the public domain name – o365info.com

The “result” results” is the host name – o365info-com.mail.protection.outlook.com which includes the “dedicated part” (o365info.com ) + the “shared path” that is identical for every Office 365 tenants (mail.protection.outlook.com)

How to get the value of our MX record from the Office 365 portal

The information about the value of the “Office 365 MX record” that represents our domain name appears in the Office 365 portal.

To be able to get this information we will need to login to Office 365 portal using Global administrator credentials.

• Login to Office 365 management portal
• On the left menu bar, click on the Setting icon
• Select the sub-menu Domains

Select the domain name which you want to view his DNS settings

• In our example, we select the registered domain name – o365info.com
• In the setting window that appears, select the menu – DNS settings

• Click on the Exchange Online section

In the following screenshot, we can see the information about the DNS records

We want to know what is the value of the MX record that Office 365 creates for our publicly registered domain name.

In our example, the value of the MX record is – o365info-com.mail.protection.outlook.com