To build the Greylisting sample agent, you must first install Visual Studio .NET 2005 and the Microsoft .NET Framework version 2.0 on the Edge Transport server.
After you install the required software, open the GreylistingAgent.csproj C# project by using Visual Studio .NET. If necessary, update the references to the Microsoft.Exchange.Data.* namespaces. Build the project and fix any errors you encounter. This will build GreylistingAgent.dll.