This problem occurs because the Exchange SMTP Service extensions are either missing or corrupted. This behavior causes loss of functionality between Exchange and the SMTP Service. The SMTP Service is a necessary service that is installed as a subcomponent of Microsoft Internet Information Services (IIS).

The error may occur for the following reasons:

• IIS has been removed.
  
  
• The SMTP Service subcomponent has been removed from IIS.
  
  
• IIS has been removed, and then reinstalled as a Windows component that does not have the required SMTP Service subcomponent.
  
  
• IIS has been removed and then reinstalled as a Windows component that has the appropriate list of subcomponents. However, the Exchange SMTP Service extensions have not been reinstalled.
  
  

This error applies to the following versions of Exchange server:

• Microsoft Exchange Server 2003
  
  
• Microsoft Exchange 2000 Server
  
  

To resolve this error, see Microsoft Knowledge Base article 326305, The Information Store does not start and MSExchangeIS Event ID 5000 and 9538 messages occur in Exchange 2000 Server and Exchange Server 2003.

To restore SMTP service extensions

1. Confirm that the Exchange SMTP Service extensions are missing. To do this, follow these steps:

   1. Log on to the computer that is running Microsoft Exchange by using an account that has administrative credentials.
      
      
   2. Click Start, click Run, type cmd, and then click OK.
      
      
   3. Type telnet 127.0.0.1 25 at the command prompt to view the "220 server.domain.com Microsoft ESMTP Mail Service" entry.
      
      
   4. Type EHLO, and then press Enter to view a list of 250 command verbs.If there are no verbs whose names start with "X," the SMTP Service Extensions are missing.
      
      

2. Completely back up the system partition. Include the system state and the Exchange database files. For more information about how to do this, see Microsoft Knowledge Base article 258243, How to back up and restore an Exchange computer by using the Windows Backup program.

3. Confirm that IIS has been correctly reinstalled to include the required Exchange-dependent subcomponents.

   IIS 6.0

   1. Click Start, point to Settings, and then click Control Panel.
      
      
   2. Double-click Add/Remove Programs.
      
      
   3. In the left pane, click Add/Remove Windows Components.
      
      
   4. In the Windows Components wizard, locate Application Server in the list of components, and then click Details.
      
      
   5. If any of the following components are not installed, install them:
      
      ASP.NET
      
      Enable network COM+ access
      
      Internet Information Services (IIS)
      
      
   6. Click Internet Information Services (IIS), and then click Details
      
      
   7. If any of the following components are not installed, install them:
      
      Common Files
      
      Internet Information Services Manager
      
      NNTP Service
      
      SMTP Service
      
      World Wide Web Service
      
      
   8. Click OK two times. On the main Windows Components page, click Next, and then click Finish.
      
      

   IIS 5.0

   1. Click Start, point to Settings, and then click Control Panel.
      
      
   2. Double-click Add/Remove Programs.
      
      
   3. In the left pane, click Add/Remove Windows Components.
      
      
   4. In the Windows Components Wizard dialog box, locate Internet Information Services (IIS) in the list of components. If the Internet Information Services (IIS) check box is selected, IIS is installed. To view the IIS subcomponents that are installed, click Internet Information Services (IIS), and then click Details.
      
      
   5. If IIS is not installed, click to select the Internet Information Services (IIS) check box, and then click Details. Install the IIS 5.0 subcomponents, and then click OK. The minimum IIS 5.0 subcomponents that are required before you install Exchange 2000 are as follows:
      
      Common files
      
      Internet Information Services snap-in
      
      SMTP service
      
      Network News Transfer Protocol (NNTP) service (for newsgroups)
      
      World Wide Web service
      
      
   6. Click Next, and then click Finish.
      
      

4. Restore the Exchange SMTP Service extensions.

   Exchange Server 2003

   If you reinstall Exchange 2003 over an existing Exchange 2003 installation, the database files and permissions remain intact. To do this, follow these steps:

   1. Insert the Exchange 2003 CD.
      
      
   2. In the \SETUP\I386 folder, double-click the Setup.exe file.
      
      
   3. On the Welcome page, click Next until you reach the Component Selection page.
      
      
   4. On the Component Selection page, click Reinstall in the Action column, and then click Next.
      
      
   5. Verify the selection on the Installation Summary page, and then click Next to continue the Exchange 2003 installation.
      
      

   Exchange 2000 Server

   The methods that you can use to restore the Exchange 2000 SMTP Service extensions depend on how many IIS subcomponents were removed. If the SMTP Service is the only IIS subcomponent that was removed, and Exchange 2000 Server Service Pack 2 (SP2) or a later service pack has been installed, use the Smtpreinstall.exe command-line utility. The Smtpreinstall.exe command-line utility is located in the Server\Support\Utils\I386 folder.

   To use the Smtpreinstall.exe utility

   1. Copy the Smtpreinstall.exe file to the Exchsrvr\Bin folder.
      
      
   2. At the command prompt, change to the Exchsrvr\Bin folder, and then type the following command:
      
      smtpreinstall.exe
      
      
   3. Restart the computer when you are prompted.
      
      

   If IIS 5.0 was removed as a component or if more than the SMTP Service subcomponent was removed from IIS 5.0, reinstall Exchange 2000 over the existing installation as part of the integrated setup of Microsoft Small Business Server 2000.

   To reinstall Exchange 2000 Server

   Note:
   If you reinstall Exchange 2000 over an existing Exchange 2000 installation, the database files and permissions remain intact.

   1. Insert the Exchange 2000 Server CD.
      
      
   2. In the \SETUP\I386 folder, double-click the Setup.exe file.
      
      
   3. On the Welcome page, click Next.
      
      
   4. Enter your CD key if you are prompted, and then click Next.
      
      
   5. On the Component Selection page, click Reinstall in the Action column, and then click Next.
      
      
   6. Verify the selection in the Installation Summary page, and then click Next to continue the Exchange 2000 installation.
      
      

5. Reinstall the Exchange service packs and hotfixes.

   For more information, see the following Microsoft Knowledge Base articles:

   836993 How to obtain the latest service packs for Exchange Server 2003.

   301378 How to obtain the latest Exchange 2000 Server service pack.