On a Windows 2000-based server that is running the SMTPSVC service with dual Network Interface Cards (NIC) installed, each bound to unique IP addresses as follows when you attempt to start the SMTP virtual server that is configured to use the 10.1.2.250 IP address bound to NIC 2 (not "All Unassigned") on Windows 2000, the following is recorded in the Application event log: If you telnet to the 250 address on port 25 while the virtual server is not running, you get no response. The third-party utility is not listening on that IP. You can stop the third-party software, and then the virtual server will start.

If you run the netstat -an command, it returns the following information when the default virtual server is started: This shows that the SMTP virtual server is listening on all unassigned IP addresses even though you specified only the 10.1.2.250 IP address.

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The SMTP service listens to port 25 on all unassigned IP addresses even if you specify a specific IP address for the default virtual server. You need to disable the Microsoft Internet Information Services (IIS) socket pooling feature (DisableSocketPooling). This property is not exposed in ADSI for SMTP.

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The easiest way to resolve this issue is to download MetaEdit, and then set the value on the virtual service instance.

WARNING: If you edit the metabase incorrectly, you can cause serious problems that may require you to reinstall any product that uses the metabase. Microsoft cannot guarantee that problems that result if you incorrectly edit the metabase can be solved. Edit the metabase at your own risk.

NOTE: Always back up the metabase before you edit it.

1.	Install and run MetaEdit on the server. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: 232068 (http://support.microsoft.com/kb/232068/EN-US/) FILE: How to Download, Install, and Uninstall the IIS MetaEdit 2.2 Utility
2.	Expand LM and SmtpSvc.
3.	Right-click SmtpSvc, click New, and then click DWORD.
4.	In the Id list, click DisableSocketPooling. The field to the right should now read 1029. If DisableSocketPooling is not in the list, click (Other), and then type 1029 in the box.
5.	In the Data field, type 1.
6.	Click to select the Inherit attribute.
7.	Restart the Simple Mail Transport Protocol (SMTP) service.

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This behavior is by design.

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