What is a smart host?

Applies To: Windows SBS 2008

A “smart host” (also known as a relay host) is a dedicated server through which Exchange Server routes all outgoing messages. The smart host then forwards the message to the remote domain. When you designate a smart host, your Exchange Server needs to transmit only to the smart host instead of repeatedly contacting the remote domain until a connection is made. This improves the performance of your server and the reliability of your e-mail delivery.