Mail relaying occurs when mail is forwarded from someone else through your mail server. Forwarding mail through a mail server is perfectly natural as long as either the originator of the message or the receiver is a authorized user. If neither the sender nor the recipient of the message is a local user, it is called third-party mail relaying.

Open relay protection

If a mail server allows third-party mail relaying from everyone, it is known as an open relay. Such a mail server attracts spammers as it can be used to send large amounts of junk mail under false identity. Our appliances come with built-in open relay protection.