When a gateway is installed, the Microsoft Exchange Server is informed of the address types for which the gateway can deliver messages. For example, an RFC-822 gateway would declare itself as able to deliver messages addressed to recipients with the SMTP address type. You can configure your gateway to accept mail only for a subset of the address type’s domain. For example, an organization might install two PROFS gateways, one to deliver mail to PROFS NODE1, and the other to deliver mail to PROFS NODE2. A gateway can also service more than one address type.
The set of address types and subtypes that the gateway can service is called the gateway’s address space.
Address space information is saved in the Routing-List attribute of the gateway’s Mail-Gateway directory object. It can be set programatically, or manually from the Address Space property page in Microsoft Exchange Server Administrator.
The gateway’s address space information is incorporated into the Microsoft Exchange Server’s Gateway Address Routing Table (GWART), which is then used to determine the routing of mail messages within the system.