Configuring Recipient Policies
Exchange uses recipient policies to determine which messages must be accepted and internally routed to mailboxes in your organization. Recipient policies that are configured incorrectly can disrupt message flow for some or all recipients in your messaging system. Recipient policies are configured in Exchange System Manager under the Recipients container in Recipient Policies.
To make sure that your recipient policies are configured correctly, verify the following:
That recipient policies do not contain an SMTP address that matches the fully qualified domain name (FQDN) of any Exchange server in your organization. For example, if you have an Exchange server with an FQDN of server01.contoso.com and you also have this same FQDN (@server01.contoso.com) listed as an SMTP address and as a domain name on any recipient policy, this entry prevents mail from routing to other servers in the routing group.
That the domain for which you want to receive SMTP mail is listed on a recipient policy—either on the default policy or another recipient policy. By verifying this information, you make sure that your users can receive mail from other SMTP domains.
That you configured the required SMTP e-mail addresses to receive e-mail messages for additional domains. If you are not receiving e-mail messages for all your SMTP domains, you might have to configure additional SMTP addresses for your recipients. For example, some of your users may currently receive e-mail messages addressed to contoso.com, but you also want them to receive e-mail messages addressed to adatum.com. In this situation, the SMTP address of @adatum.com and the SMTP address of @contoso.com must exist on a recipient policy for your Exchange organization.
For more information about recipient policies, see "Managing Recipients and Recipient Policies in Exchange Server 2003."