Relay

Definition

A relay is a system acting as an interim station for the provision of a service. In connection with malware and spam, relays are used to conceal the real sender and prevent blocking. Open SMTP relays are of particular note. These are computers that accept e-mails from any given computer and forward them to third parties, even though they are not responsible for the e-mails of either party. Botnets are often also used for relay purposes. Internet Relay Chat (IRC) is also significant in this connection, since it is often abused as a communication interface for botnets.