Authentication on a socket

Question

Hi,
I'm using a socket to connect to an SMTP server in order to send mail. However, I have to be able to authenticate on that socket. How would I be able to state my user name and password when opening the connection to the socket?
try { // Open port to server
  System.getProperties().put("mail.host", "HOST");
  m_sHostName = System.getProperty("mail.host");
  smtpSocket = new Socket(m_sHostName, m_iPort);
  dos = new DataOutputStream(smtpSocket.getOutputStream());
  dis = new DataInputStream(smtpSocket.getInputStream());
  if(smtpSocket != null && os != null && is != null)
  { // Connection was made.  Socket is ready for use.
     System.out.println("CONNECTION MADE");
catch(Exception e) {
System.out.println("Host " + m_sHostName + " unknown");
}

Answer 1

After you have connected, your program converses with the server program according to the RFC822 protocol (and probably other SMTP-related protocols). Authentication is part of that protocol, so just read the document.
Alternatively, use the JavaMail package that encapsulates all of that for you.