What is it?
Mail exchange record, or also called just MX record, is a DNS resource record. The Domain Name System (DNS) applies it to point accurately to the proper name of the incoming email server where emails have to be sent. DNS records are the essential part of providing instructions for various DNS processes. In this case, the MX record is giving the instruction that a particular server has to receive the emails sent to a defined domain.
How to create a DNS MX record?