What does an Mail Exchanger (MX) record do?

A Mail Exchanger (MX) record is integral to the functioning of email within the domain name system (DNS). It specifically indicates which mail server is responsible for receiving incoming mail on behalf of a domain. When an email is sent, the sending mail server queries the DNS to find the MX record associated with the recipient's domain. The MX record points to the server that should receive the email, ensuring that it is directed to the correct destination.

This mechanism is crucial for email delivery, as it allows for the routing of messages over the Internet to the appropriate email servers. Without the MX record, email systems would not know where to send messages, leading to failed deliveries and communication breakdowns.

In contrast, the other choices describe functions that are not related to what an MX record does. For example, mapping domain names to email clients, storing draft emails, and encrypting messages are all processes that involve different aspects of email communication and technology, but they do not pertain to the role of an MX record in directing incoming email traffic.