MX Record of a Domain: What It Is, Viewing, and Checking

MX record (Mail eXchange) is an MX-type DNS record that points to the domain names of mail servers receiving incoming mail for a specific domain.

In other words, when someone sends an email to an address on your domain, the sender's mail system queries DNS to determine the MX records of the corresponding domain. This information is essential for the proper functioning of mail services, as incorrectly configured MX records will result in messages being returned to the sender.

How Do MX Records Work?

When the sender sends an email, their mail server requests the MX records of the recipient's domain from DNS. From the list of available mail servers, the one with the lowest numeric priority is chosen. For example, a server with priority "10" is preferred over "20" or "30." If the primary server is unavailable, the process continues with the next one in the list. As a result, the message is delivered to the mail server specified in the MX record, and the user receives the email addressed to their domain.

Checking MX Records of a Domain

You can make sure your MX records are configured correctly in several ways. Here are some verification options:

1. Command line tools (Windows, Linux, macOS): In Windows, use the command nslookup -type=MX example.com, while Linux or macOS typically use dig MX example.com. These tools display the record, server name, and priority.
2. Online services: There are websites where you can enter your domain and instantly get results. For example, "MXToolbox" or "IntoDNS" display MX records and point out potential issues.
3. WHOIS systems: Some whois-focused platforms may also display basic DNS configuration data, including mx-record.

How to Configure or Change MX Records?

If you want to route emails to another server or set up an external mail service (e.g., Google Workspace), add or edit MX records. This is typically done in your hosting DNS panel or domain registrar. You need to specify:

• Name (usually "@" or the domain itself)
• Type "MX"
• Value (the server address, e.g., mail.example.com)
• Priority (a number that defines the order)

After saving changes, allow some time for DNS updates—usually from a few minutes to several hours. Then, another check will be performed to ensure the changes have taken effect.

Common Mistakes

Carelessness during MX record configuration often leads to email delivery issues. Here are some common problems:

• Missing the "dot" in the name: when specifying mail.example.com, people often forget to add the final dot or make typos;
• Duplicate records with different priorities: if two identical MX records exist with different priorities, some emails may be delivered to "unexpected" locations;
• Old, outdated entries: when transferring a domain, people sometimes forget to remove legacy records from the previous provider;
• Incorrect priority: a too-high priority value on the main server interferes with fallback mechanisms;
• Conflicting settings in hosting panels and external DNS: a domain may be managed in two places at once, causing conflicts and confusion.

FAQ

How Do MX Records Affect Domain Reputation?

Incorrectly configured MX records can result in emails being returned to the sender, which negatively affects the domain's reputation. Proper MX records pointing to reliable mail servers increase trust in the domain.

Why Am I Not Receiving Email on My Domain?

There may be several reasons: incorrectly configured MX records, issues with the mail server, or your domain's mail servers being blacklisted.

How Can I Check If My Mail Servers Are Blacklisted?

You can use online services that analyze IP addresses for presence in blacklists. You can also check logs for errors or block notifications.