A server used to send or receive Internet mail. Specifically, MX refers to a type of DNS record that specifies the server handling the mail for a given host or domain.

A Mail eXchanger is a type of DNS record that allows you to redirect mail for a given domain or subdomain. MX records can be set on a host-by-host basis to point to other hosts on the Internet (usually with permanent connections) that are set up to accept and/or route mail for your hostname(s). Setting a Backup MX makes the entry you specify a secondary mail exchanger. This means that delivery will be attempted to your host first, and then to the host you specify if that fails. () () () () () ()

a computer that receives mail for another domain name

A system used to relay mail into a network.

Resource records that are used in e-mail applications to find a mail server that corresponds to the destination address in an e-mail.