Topic Last Modified: 2009-02-17

When you run the Microsoft Exchange Server Best Practices Analyzer during the installation of Exchange Server 2007, the tool examines the organization to determine whether the following conditions are both true:

If these conditions are both true, the Best Practices Analyzer generates the following warning message:

Setup cannot detect an SMTP or Send connector with an address space of '*'. Mail flow to the Internet may not work properly.

When you install Exchange 2007 into an Exchange 2003 organization, each Exchange server should have at least one SMTP virtual server that is not configured to use a smart host. Alternatively, you should configure an SMTP connector that uses a smart host together with an address space of *.

If the Exchange 2003 SMTP virtual server is configured to use a smart host and if an SMTP connector with an address space of * does not exist, you may experience mail flow issues between Exchange 2003 and Exchange 2007.

When you install Exchange 2007 in an Exchange 2003 organization, the Setup program creates a bidirectional connector between Exchange 2003 and Exchange 2007. To do this, the Setup program uses the new-RoutingGroupConnector cmdlet. If the Exchange 2003 server has a smart host configured on the SMTP virtual server, mail flows from Exchange 2007 to Exchange 2003 as expected. However, mail does not flow from Exchange 2003 to Exchange 2007.

To address this issue, remove the smart host entry from the Exchange 2003 SMTP virtual server. Or, create an SMTP connector that has an address space of *.

To modify the SMTP virtual server in Exchange 2003

  1. Start the Exchange System Manager tool.

  2. Expand the following nodes:

    • Administrative Groups

    • <YourAdministrativeGroup>

    • Servers

    • <YourExchangeServer>

    • Protocols

    • SMTP

  3. Right-click the appropriate SMTP virtual server, such as Default SMTP Virtual Server, and then click Properties.

  4. Click the Delivery tab, and then click Advanced.

  5. Delete the entry in the Smart host box, and then click OK two times.

  6. Right-click the SMTP virtual server, and then click Stop.

  7. Right-click the SMTP virtual server, and then click Start.

For information about how to create an SMTP connector in Exchange 2003, see Microsoft Knowledge Base article 265293, How to configure the SMTP connector in Exchange 200x.