MX Record

The characteristic information in an MX record is the fully qualified domain name of a mail host and a preference value. The host name must map directly to one or more address record (A, or AAAA) in the DNS, and must not point to any CNAME records.

When an e-mail message is sent through the Internet, the sending mail transfer agent queries the Domain Name System for MX records of each recipient's domain name. This query returns a list of host names of mail exchange servers accepting incoming mail for that domain and their preferences. The sending agent then attempts to establish an SMTP connection to one of these servers, starting with the one with the smallest preference number, delivering the message to the first server with which a connection can be made. If no MX records were present, the server falls back to A, that is to say, it makes a request for the A record of the same domain.

• For domains hosted by Imaginet, the MX records are pointed to default-mx.imaginet.co.za, which in turn translates to the IP of our mail server.
• Many clients make use of Google to host their mail. In this case, the client will have a number of MX records, all pointing to various Google servers. These records will be prioritised differently. The following example uses the imaginet domain. This is how imaginet.co.za's MX records would look if we hosted our mail with Google: