drag and drop using post/sendmessage

I am trying to find a way to preform drag and drop using API function SendMessage() or PostMessage(), I am using the following code but its not working:

API.Click(controlHandleStart, false, (ushort)RelativePointStart.X, (ushort)RelativePointStart.Y);//mouse down

System.Threading.Thread.Sleep(200);

API.Click(controlHandleEnd, true, (ushort)RelativePointEnd.X, (ushort)RelativePointEnd.Y);//mouse up

Basically what I am trying to do is to preform a drag and drop for an email in outlook I want to drag an email and drop it into a folder within outlook but i need to use post/sendmessage.

I just sending the mouse down on the drag location and then I send the mouse up on the drop location, I am not able to fin开发者_如何学Cd way to send the mouse move message.