An e-mail message that is addressed to a recipient on an external domain is unexpectedly forwarded through an Exchange Server 5.5 server in an Exchange 2000 Server mixed-mode topology (320504)


The information in this article applies to:

  • Microsoft Exchange 2000 Server
This article was previously published under Q320504

SYMPTOMS

Consider the following scenario. You are working in a mixed-mode topology that contains Microsoft Exchange Server 5.5 and Microsoft Exchange 2000 Server. On an Exchange 2000 server, you create an e-mail message that is addressed to a recipient on an external domain. Then, you send the e-mail message. In this scenario, the e-mail message is unexpectedly forwarded through an Exchange Server 5.5 server before the message is sent to the recipient on the external domain.

CAUSE

This behavior occurs if the Internet Mail Service on one of the Exchange Server 5.5 servers contains an address space that is set to *. This setting is a wildcard character that indicates all external domains. If the address space is set to *, the Internet Mail Service on the Exchange Server 5.5 server takes message routing precedence over the Simple Mail Transfer Protocol (SMTP) connector on an SMTP virtual server in Exchange 2000. Therefore, outgoing SMTP messages that originate on the Exchange 2000 server are routed through the message transfer agent (MTA) service to the Internet Mail Service on the Exchange Server 5.5 server.

WORKAROUND

If you want all SMTP mail to be sent from the Exchange 2000 server instead of through the Exchange Server 5.5 server, follow these steps:
  1. Remove the Internet Mail Service address space from the Exchange Server 5.5 server. To do this, follow these steps:
    1. On the Exchange Server 5.5 server, click Start, point to Programs, point to Microsoft Exchange, and then click Microsoft Exchange Administrator.
    2. Expand ExchangeServerName, expand Configuration, and then click Connection.
    3. Double-click Internet Mail Service, and then click the Address Space tab.
    4. Click the address space that you want to remove, click Remove, and then click OK.
    5. Quit the Microsoft Exchange Server Administrator program.
  2. In Exchange System Manager, create an SMTP connector that has a specific address space match. To do this, follow these steps:
    1. On the Exchange 2000 server, click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
    2. Expand Administrative Groups, expand First Administrative Group, expand Routing Groups, and then expand First Routing Group.
    3. Right-click Connectors, click New, and then click SMTP connector.
    4. Type the name of the connector in the Name box, click the Address Space tab, and then click Add.
    5. Click SMTP, and then click OK.
    6. In the Internet Address Space Properties dialog box, type a specific address space in the E-mail domain box, and then click OK.
  3. Designate an Exchange 2000 SMTP virtual server to act as the local bridgehead server. To do this, follow these steps:
    1. Start Exchange System Manager, and then open the SMTP connector properties.
    2. On the General tab, click Add under Local bridgeheads.
    3. Click the SMTP virtual server that you want to act as the local bridgehead server, and then click OK.
    4. Quit Exchange System Manager.
  4. Configure the address space of the SMTP virtual server. To do this, follow these steps:
    1. Start Exchange System Manager, and then open the SMTP connector properties.
    2. On the Address Space tab, type * in the SMTP address box.
    Note Make sure that the SMTP virtual servers that you want to use are listed as local bridgehead servers.
If you want SMTP mail to be sent from both the Exchange Server 5.5 server and the Exchange 2000 server, follow these steps:
  1. Complete steps 1 to 4 that are mentioned in this section.
  2. Create a second routing group. To do this, follow these steps:
    1. On the Exchange 2000 server, click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
    2. Expand Administrative Groups, and then expand First Administrative Group.
    3. Right-click Routing Groups, click New, and then click Routing Group.
    4. Type the name of the routing group in the Name box, and then click OK.
    5. Quit Exchange System Manager.
  3. Move the Exchange 2000 server to the new routing group.
When you complete these steps, the Internet Mail Service on the Exchange Server 5.5 server is contained. Therefore, Exchange uses the SMTP connector instead of the Internet Mail Service. The SMTP connector has a more specific address space match than the Internet Mail Service. Additionally, you can scope the address space on the Internet Mail Service to the site setting after you move the Internet Mail Service to a new routing group.

STATUS

This behavior is by design.

MORE INFORMATION

An Exchange 2000 server can route external SMTP mail from an SMTP virtual server if you configure host name resolution. If you configure host name resolution, you do not have to configure an SMTP connector. The default address space for message routing for the SMTP virtual server is a wildcard character (*). The routing engine uses this address space when you try to send mail to an external domain from an Exchange 2000 server that does not have a configured SMTP connector. If the Internet Mail Service has an explicitly stated SMTP address, the Exchange 2000 routing engine will use this address space instead of the wildcard address space on the SMTP virtual server. Therefore, outgoing mail to an external domain will first be routed to an Exchange Server 5.5 server through the MTA service on the Exchange 2000 server.

For more information about Exchange Server transport and routing, visit the following Microsoft Web site:

http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/extransrout.mspx

For more information about how Exchange Server 5.5 determines the best match for address spaces, click the following article number to view the article in the Microsoft Knowledge Base:

152471 Difference between SMTP:* and SMTP: Address space

Modification Type:MajorLast Reviewed:8/25/2005
Keywords:kbexchTRANSPORT kbprb KB320504 kbAudITPRO
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