MXrecords

MX records are a type of DNS record that allows email servers to determine whether an email should be delivered to a mailbox or rejected by a spam filter. They are used by email providers to query which mail servers are responsible for handling email for a particular domain.

MX records are used in conjunction with DNS (Domain Name System) to handle email delivery. When an email is sent from one email server to another, the sending email server queries the DNS for the MX records associated with the recipient's domain. The MX records are used to determine which mail server is responsible for receiving email for that domain.

Typically, MX records contain a priority value, which indicates the order in which mail servers should be queried for email delivery. The mail server with the highest priority value will be queried first, and if it is unavailable, the next mail server will be queried using the next MX record. This allows email providers to set up a hierarchy of mail servers that can handle email delivery for a particular domain.

Mail servers use the following sequence of operations to handle an email delivery: (1) the sending email server queries the DNS for the MX records associated with the recipient's domain, (2) the mail server with the highest priority value is queried for email delivery, and (3) if the high-priority mail server is unavailable, the sending email server will query the next mail server using the next MX record.