XFOR: Causes for Event ID 4018 when starting the IMC (163243)

SYMPTOMS

When you start the Internet Mail Connector (IMC), you may receive the following error message:

Error 2140: An internal Windows NT error occurred.

The following event is logged in the application event log:

   Event ID: 4018
   Type: Error
   Source: MSExchangeIMC
   Category: Initialization/Termination
   Description:

   Unable to start the Internet Mail Connector service because
   MAPI could not be initialized.

CAUSE

If you receive this error, check the following:

Verify that Mapisvc.inf is located in the proper folder. It should be in the %System Root%\System32 folder.
Verify that the Exchange Service Account has at least change rights on the Mapisvc.inf file in the <systemroot>\System32 folder.
Verify that you have a private information store on that server. For more information, see the following article in the Microsoft Knowledge Base:
157042 Event ID 4018 if IMC Started Without Private IS
Verify that the CommonName and HomeDSA registry entries are present and valid. They will be listed under:
```
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIMC
   \Parameters
```

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

147935 XFOR: Behavior of IMC With Invalid Registry Information

186739 Events 4018 and 4116 Starting the Internet Mail Service