Although the SMTP service starts, the SMTP virtual server does not start in Exchange 2000 Server

The Simple Mail Transfer Protocol (SMTP) service starts, but the SMTP virtual server does not start in Microsoft Exchange 2000 Server. Additionally, an event that is similar to the following event is logged in the Application log:

This problem occurs if a third-party program is using TCP port 25. By default, TCP port 25 is the port that is assigned for SMTP mail. Some third-party antivirus and content filtering programs monitor TCP port 25. These programs forward SMTP mail from port 25 to another port.

To resolve this problem you must identify the port to which the third-party antivirus or content filtering program forwards SMTP mail. Then, you must change the port for the SMTP service.

To identify and change the port, follow these steps:

1. Verify whether any third-party programs are running on the Exchange 2000 Server server for SMTP virus protection or for content filtering.
2. Disable these programs, and then start the SMTP virtual server. To start the SMTP virtual server, follow these steps:
   1. Start Exchange System Manager.
   2. Expand Administrative Groups, expand Your_Administrative_Group, and then expand Servers.
   3. Expand Your_Exchange_Server_Name, and then expand Protocols.
   4. Click Default SMTP virtual server, and then click Start.
      
      Note If the SMTP virtual server starts, the third-party program that you disabled is blocking the SMTP default port. In this case, quit Exchange System Manager, and then complete the remaining steps that are described in this section.
      
      If the SMTP virtual server does not start, you must follow other troubleshooting methods to resolve this problem.
3. See the third-party program documentation or Help file to identify the port to which the program forwards SMTP mail. You may have to contact the manufacturer of the product to obtain this information.
4. Locate the Services file.
   • In Microsoft Windows Server 2003, the Services file is stored in the following folder:
     %Systemroot%\WINDOWS\System32\Drivers\etc\Services
   • In Microsoft Windows 2000 Server, the services file is stored in the following folder:
     %Systemroot%\WINNT\System32\Drivers\Etc\Services
5. Use Notepad to open the Services file, and then locate the SMTP Service information.
   
   In a typical Services file, default entries appear at the top of the file. Then, entries for each service appear below the default entries. The following text is an example of a Services file that includes the default entry for the SMTP service:
   

   # Copyright (c) 1993-1999 Microsoft Corp.
   #
   # This file contains port numbers for well-known services defined by IANA
   #
   # Format:
   #
   #<service name><port number>/<protocol> [aliases...] [#<comment>]
   #
   
   smtp 25/tcp mail #Simple Mail Transfer Protocol

6. Change the SMTP service entry as required. For example, if the third-party program requires the SMTP service to listen on port 2525, change the SMTP entry to the following:
   
   smtp 2525/tcp mail #Simple Mail Transfer Protocol
7. Save the file, and then quit Notepad.
8. Use either of the following methods to restart the SMTP service:
   • Restart the SMTP service from the Services snap-in:
     1. Click Start, click Run, type services.msc, and then click OK.
     2. Right-click the SMTP service, and then click Restart.
   • Restart the SMTP service at a command prompt:
     1. Open a command prompt.
     2. Type the following command, and then press ENTER:
        net stop smtpsvc && net start smtpsvc
     3. Type exit, and then press ENTER.
   .
9. Enable the third-party programs that you disabled in step 2.

For information about your hardware manufacturer, visit the following Web site: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

For more information, click the following article number to view the article in the Microsoft Knowledge Base: