What Is a DNS MX Record?

A Domain Name System (DNS) mail exchange (MX) record directs emails to a particular mail server. As such, it indicates how emails should be routed according to the Simple Mail Transfer Protocol (SMTP). It must always point to another domain.

If the DNS is the Internet’s phonebook, a DNS MX record is a specific person’s home address. Anyone who wishes to see or talk to the person can do so by going to the address.

Other interesting terms…

Read More about a DNS MX Record

All email addresses should have a DNS MX record if their owners wish for people to be able to contact them electronically.

What DNS MX Record -Related Terms Should You Become Familiar With?

Here are a few terms you should become familiar with when dealing with DNS MX records.

DNS

The DNS is a computer naming system on the Internet. In essence, it is a database that maps an IP address to its corresponding domain name. The DNS is critical because computers can only read IP addresses while people reach websites using their domain names.

MX Server

An MX server, also known as a “mail server” or an “email server,” is a computerized system that facilitates sending, receiving, and storing email. As such, it serves as a central email communication hub that manages the flow of messages between email clients like Outlook or Gmail and the Internet.

SMTP

SMTP is a technical standard for transmitting emails over a network. Like other networking protocols, it lets computers and servers exchange data regardless of their underlying hardware or software. Simply put, you and your message recipient can communicate via email no matter what device, operating system (OS), or ESP you and your message recipient use. So, when you send an email using Gmail on your iPhone, recipients can view it on Outlook using their computer.

What Does a DNS MX Record Contain?

A DNS MX record for the email address john_doe@example.com contains the information in the table below.

DOMAIN	PRIORITY	MX SERVER	TTL
example.com	10	mailhost1.example.com	45000
example.com	20	mailhost2.example.com	45000

Email domain: Found after the @ sign in an email address.

Priority: Indicates the preference in terms of MX server usage. The lower priority value is always preferred. As such, the MX server will always try mailhost1.example.com first because 10 is lower than 20. If it fails to send the message, the server will default to mailhost2.example.com.

Time to live (TTL): Determines the number of seconds before subsequent changes like modifying the mail server go into effect. If you change the priority value of mailhost1.example.com to 20, for example, the modification will only take effect after 45,000 seconds or 12.5 hours.

How Do You Set Up a DNS MX Record ?

Setting up DNS MX records is similar for most email and domain providers. Note, however, that you will need the help of your email service provider (ESP) to obtain your MX record values.

If you want a step-by-step guide, follow these instructions:

Get the MX record values from your ESP.
Sign in to your domain registrar’s portal.
Add a new DNS record.
Select MX in the Type field.
Enter the @ symbol in the Name or Hostname field.
Paste your MX server address into the Value or Destination field.
In the TTL field, leave the default entry or enter 3600 seconds or 1 hour.
If multiple MX records exist, enter priority numbers in the Priority field. Remember that the lower number has higher priority.
Save the record and wait for it to be published in your domain’s DNS.

How Can You Search for a DNS MX Record ?

You learned how to create a DNS MX record from scratch earlier, but you can also make changes to an existing one if needed. If you want to find out more about your MX record but don’t have the time to contact your ESP, you can use a web-based DNS lookup tool or an MX record lookup.

If you wish to know the MX servers of john_doe@example.com, type the domain name (i.e., example.com) into the input field and click Lookup. Here’s the result.

Key Takeaways

A DNS MX record directs emails to a particular mail server. As such, it indicates how emails should be routed according to the SMTP. It must always point to another domain.
An MX record typically contains the email domain and its corresponding priority values, MX servers, and TTL values.
You will need the help of your ESP if you want to create MX records.