MX RECORD (Mail Exchange Record)

[subornaakter20]

An MX record contains the address where emails sent to a particular domain should be sent.

For example, if the email address is "[email protected]", the domain is "arara.com".

If the name of the domain's mail server (called the host name) is "mail.arara.com", the MX RECORD should be written as "arara.com. IN MX 10 mail.arara.com".

This says, "Deliver emails addressed manufacturing email list to 'arara.com' to the mail server called 'mail.arara.com'!"

"IN" stands for Internet, "MX" stands for MX RECORD, and "10" stands for priority when multiple mail servers are set up for the same domain.

This priority is generally written as a number such as 10 or 20, and the smaller the number, the higher the priority.


When an email is delivered, the destination email server must first be obtained from the MX RECORD, and then the IP address of that email server must be obtained from the A RECORD, so both settings are required in DNS.

In other words, when displaying a website as shown in the diagram of 【How DNS works①】, DNS only references the A RECORD.


On the other hand, when delivering email, DNS refers to the MX RECORD and A RECORD simultaneously to identify the IP address of the mail server from the domain, as shown in the figure below.


[How DNS works ③ (behind the scenes of name resolution/example of sending email)]