Mike I think there is here a miscomunication, so lets recap.
your client app sends a message to a server app that is a 3rd party app when that server app receives the message what happens, does it generates an event? or just show a message box?
How do you know that the 3rd party server app received a message?

>Hi Alexandre,
>
>I also tried the following code but it produces the same result when received by the server application:
>
>string msg = this.textBox1.Text;
>m_clientSocket.DontFragment = true;
>m_clientSocket.SendBufferSize = 1024;
>NetworkStream networkStream = new NetworkStream(m_clientSocket);
>
>System.IO.StreamWriter streamWriter = new System.IO.StreamWrite(networkStream);
>streamWriter.Write(msg);
>streamWriter.Flush();
>
>How can I send it as a whole string so that the server application will receive it as a string?
>
>Thanks in advance...