Example of how to call Powershell Pipeline in C# and bring in Exchange SnapIn

     public List<string> getBlockedSenders()  
     {  
       RunspaceConfiguration rsConfig = RunspaceConfiguration.Create();  
       PSSnapInException snapInException = null;  
       PSSnapInInfo info = rsConfig.AddPSSnapIn("Microsoft.Exchange.Management.PowerShell.E2010", out snapInException);  
       Runspace myRunSpace = RunspaceFactory.CreateRunspace(rsConfig);  
       myRunSpace.Open();  
       Pipeline ps = myRunSpace.CreatePipeline();  
   
       Command getSenderFilterConfigCommand = new Command("Get-SenderFilterConfig");  
       ps.Commands.Add(getSenderFilterConfigCommand);  
   
       Command selectObjectCommand = new Command("Select-Object");  
       CommandParameter selectObjectArgs = new CommandParameter("ExpandProperty", "BlockedSenders");  
       selectObjectCommand.Parameters.Add(selectObjectArgs);  
       ps.Commands.Add(selectObjectCommand);  
   
       Command outStringCommand = new Command("Out-String");  
       CommandParameter outStringArgs = new CommandParameter("Stream");  
       outStringCommand.Parameters.Add(outStringArgs);  
       ps.Commands.Add(outStringCommand);  
   
       List<string> output = new List<string>();  
       foreach (PSObject result in ps.Invoke())  
       {  
         output.Add(result.ToString());  
       }  
   
       myRunSpace.Dispose();  
       return output;  
     }