What is a MX DNS record (Mail Exchanger Record)?

Map Of Internet 1973


The MX DNS is a DNS record that defines the mail delivery smtp server. You can only use one mail exchange server at a time for a specific domain name (ie domain or subdomain).

The name of the MX record is the last part of an email address and designates the host where the email should be delivered.

When an email is send:


When you add multiple MX records, the servers they point to must belong to the same service provider.


You can query them. For instance, the mail server of gmail can be found with a dns client such as nslookup command or Network - dig ( DNS tool)

nslookup -type=MX gmail.com
# or
dig gmail.com MX
  • if the MX record exists
gmail.com       MX preference = 10, mail exchanger = alt1.gmail-smtp-in.l.google.com
gmail.com       MX preference = 20, mail exchanger = alt2.gmail-smtp-in.l.google.com
gmail.com       MX preference = 5, mail exchanger = gmail-smtp-in.l.google.com
gmail.com       MX preference = 40, mail exchanger = alt4.gmail-smtp-in.l.google.com
gmail.com       MX preference = 30, mail exchanger = alt3.gmail-smtp-in.l.google.com

  • if the MX record does not exist, the DNS server returns the CNAME records if they exist (as specified in the reference)

Discover More
Map Of Internet 1973
DNS - Record

A DNS record is a row in a DNS database. Example of a A record. where: api is a relative name IN is the INTERNET class (An other value is ANY) A is the A record is the Ip address...
Email - Mille and one way to send an email (professional and user)

This article shows you Mille and one way to send an email (ie known as transport in SMTP. submission port Before continuing, you need to know the basics of email and how it works with SMTP. If you...
How does the email system work? SMTP, POP, IMAP explained

This page gives you the foundations of the email system. At the end, you should be able to understand why when you configure your email client, you need to set up: The SMTP configuration And the...
Dns Architecture
What is DNS ? The Domain Name System

The Domain Name System (DNS) is a database of name. It's naming system (service). It holds naming information for some kind of object (not only but mainly host) DNS can be seen as the phone book of...
Map Of Internet 1973
What is a DNS CNAME (Canonical Name) ?

A CNAME (Canonical Name) is the DNS alias functionality that maps a domain name to another name. More ...
Map Of Internet 1973
What is a DNS Zone?

A dns zone: is a namespace for a domain name (in the name hierarchical tree) is composed of all labels of a domain name except the last one on the left. DNS in foo.bar.com, the zone is bar.com...
Map Of Internet 1973
What is a Domain Name in DNS ?

The term domain name is a name: in the Domain NameSpace (DNS) that identifies an object (known also as node) in the domain database (ie a DNS database or a local host file) It's also known as...
Map Of Internet 1973
What is a Domain?

The term domain is just the equivalent short name for a DNS name (ie Domain name). For more information, check the dedicated page: This examples show how the domain name is used to define a host resource....
What is a Mail eXchange or Email mail delivery agent (MDA | LDA)?

A mail delivery agent (MDA) or Mail eXchange is a SMTP server that is responsible for the local delivery (reception) of e-mail messages to a mailbox It's also known as: message delivery agent (MDA)...
What is a SMTP Server? The server that sends, receives, and processes email

What is an SMTP server and how to implement it

Share this page:
Follow us:
Task Runner