The IMC Sample Extension DLL is included on the Microsoft BackOffice Resource Kit: Part One compact disc. You install the file to a server running the Internet Mail Connector.
1. From the Tools\Imcext directory on the Microsoft BackOffice Resource Kit: Part One compact disc, copy Imcext.dll to a server running the Internet Mail Connector.
2. Create a registry value named ExtensionDLL that points to Imcext.dll.
The key is HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIMC\Parameters. The type is REG_SZ. The value is c:\path\Imcext.dll, where path is the path to the sample extension DLL.
3. In the Imcdata directory on the Microsoft Exchange Server computer, create a configuration file named Imcroute.cfg.