Applies to: Exchange Server 2010 SP2

Topic Last Modified: 2010-08-20

In your multi-tenant organization, each tenant needs to be treated as their own organization and mail between organizations needs to appear to be coming from a separate organization. In order to do that, you need to route e-mail that goes between tenant organizations to the Internet and then back into the Hub Transport Servers for delivery.

For example, your organization hosts Alpine Ski House and Humungous Insurance. An employee at Alpine Ski House wants to send e-mail to an employee at Humungous Insurance. The employee at Humungous Insurance is on vacation and has setup internal and external automatic replies. If the e-mail from Alpine Ski House doesn't get routed to the Internet and then back to Humungous Insurance, then the Alpine Ski House employee will get the internal automatic reply.

When you first install Exchange Server SP1, out of the box it doesn't send or receive Internet mail. You need to create Send and Receive connectors. For more information, see Configure Internet Mail Flow Directly Through a Hub Transport Server.

Because mail is delivered to the Internet through a Hub Transport Server and then back through a Hub Transport server, there is the possibility that the mail could be delivered back to the same Hub Transport server that it was sent from. If this happens, then you get a message looping issue and the mail delivery will fail. In order to prevent this from occurring, we recommend that you create dedicated send connector and receive connector Hub Transport Servers.

Configure Inter-Tenant Mail Flow

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