Sending Message to IP and Port

I am using D7 and I'm trying to send an HL7 message (text message) to a
specific IP and port.

I've been using Delphi since Delphi 2, but I've never attempted to send a
"message" to a port.

I fumbled my way through and found the TUdpSocket component.

Is this the right component to use? Is there a better one that comes with
Delphi 7?

I am getting a 10038 error.  I have a listener app installed locally on my
computer. I have the TUdpSocket.LocalHost, TUdpSocket.LocalPort,
TUdpSocket.RemoteHost, TUdpSocket.RemotePort set to my internal IP and the
listener port's IP.

Here is the code I am using to test it.

procedure TForm1.Button1Click(Sender: TObject);
var
  TempResult : integer;
  TempStream : TStringStream;
begin
  TempStream := TStringStream.Create('test');
  TempResult := UdpSocket1.SendStream(TempStream);
  TempStream.Free;
  MessageDlg('Result = ' + IntToStr(TempResult), mtError, [mbOK], 0);
end;

procedure TForm1.UdpSocket1Error(Sender: TObject; SocketError: Integer);
begin
  MessageDlg('Error = ' + IntToStr(SocketError), mtError, [mbOK], 0);
end;

I am brand new to this, so bare with me.

Thanks.