Microsoft Exchange Server 2003 Deployment Guide- P57:Your Exchange Server 2003 deployment plan should reflect your understanding of how Exchange and Microsoft Windows Server™ operating systems interoperate. It should encompass the relationships between Windows Server 2003 and Microsoft Windows® 2000 Server sites and domains, domain controllers, global catalog servers, and Exchange 2003 administrative and routing groups. | 561 mail sent to contacts that have been imported into a forest should route back through the source forest. If you have a connector to a foreign messaging system by default mail that is intended for a contact is routed to the source forest the forest that manages the connector however the forest administrator can change this routing configuration. Note If Exchange is running in the forest ADC replicates the second proxy address to the Exchange directory provided that two-way connection agreements are set up. As an example of SMTP routing in a multiple forest environment consider two forests that each have a default recipient policy with an SMTP proxy address of . To set up unique namespaces you would do the following in each Exchange organization In Organization 1 add an SMTP proxy address of Org1 . to the default recipient policy. In Organization 2 add an SMTP proxy address of to the default recipient policy. 562 In both cases when adding the proxy address you would select the This organization is responsible for all mail delivery to this address check box. Also you would leave the proxy as the primary address so that when a user sends mail their reply address is user@ rather than user@ or user@ . Another example illustrates mail flow in a hub-and-spoke topology. In this example multiple Exchange organizations are present but all users can be addressed in a single domain space for example @ . In this case all external mail addressed to @ flows into a central hub organization called OrgA. OrgA is configured with secondary SMTP proxy addresses that represent each spoke organization. One of these addresses is @. When mail addressed to UserB@ arrives at OrgA the mail resolves to the contact and the mail is redirected to OrgB. When the message leaves OrgA the To line is changed to the TargetAddress property to allow for
