Mail exchanger record

A Mail Exchanger Record (MX Record) is a type of DNS record that specifies the mail server responsible for accepting email messages on behalf of a domain name. It is used to direct incoming email messages to the correct mail server.

An MX Record is a critical component of the Domain Name System (DNS) and is used to route email messages between mail servers. When an email message is sent to a domain name, the sending mail server looks up the MX Record for that domain in the DNS and uses the information to determine which mail server to send the message to.

An MX Record typically consists of the following information:

  1. Priority: A numerical value that indicates the order in which the mail server should be tried. Lower priority values are tried first.
  2. Mail Server: The hostname or IP address of the mail server responsible for accepting email messages for the domain.
  3. Domain: The domain name for which the mail server is responsible.

Here is an example of an MX Record:

IN MX 10 mail.example.com

This MX Record specifies that the mail server mail.example.com has a priority of 10 and is responsible for accepting email messages for the example.com domain.

When a sending mail server looks up the MX Record for a domain, it will try the mail server with the lowest priority value first. If that mail server is unavailable or unable to accept the message, the sending mail server will try the next mail server with the next lowest priority value, and so on.

MX Records are used to:

  1. Route email messages to the correct mail server.
  2. Ensure that email messages are delivered to the correct domain.
  3. Provide redundancy and failover capabilities for email services.
  4. Allow multiple mail servers to be used for a single domain.

It's worth noting that MX Records are typically used in conjunction with other DNS records, such as A Records and TXT Records, to provide a complete email infrastructure.