Java

import javax.mail.*;
import javax.mail.Message;
import java.util.*;
import javax.mail.internet.*;

public class Sendemail {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
            final String username="username";
            final String password="password";
            Properties prop=new Properties();
            prop.put("mail.smtp.auth", "true");
            prop.put("mail.smtp.host", "smtp.gmail.com");
            prop.put("mail.smtp.port", "587");
            prop.put("mail.smtp.starttls.enable", "true");
        
            Session session = Session.getDefaultInstance(prop,
		  new javax.mail.Authenticator() {
			protected PasswordAuthentication getPasswordAuthentication() {
				return new PasswordAuthentication(username, password);
			}
		  });
          try {
 
			Message message = new MimeMessage(session);
			message.setFrom(new InternetAddress("myemail@gmail.com"));
			message.setRecipients(Message.RecipientType.TO,
				InternetAddress.parse("receiveremail@gmail.com"));
			message.setSubject("Testing Subject");
			message.setText("Dear Mail Crawler,sNo spam to my email, please!");
                       
			Transport.send(message);
 
			System.out.println("Done");
 
		} catch (MessagingException e) {
			e.printStackTrace();
		}
            
    }
}




Please Help Someone..
    I have Exception On this code

javax.mail.MessagingException: 502 5.5.1 Unrecognized command. nw9sm29708787pbb.42

	at com.sun.mail.smtp.SMTPTransport.issueCommand(SMTPTransport.java:2080)
	at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1910)
	at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:652)
	at javax.mail.Service.connect(Service.java:317)
	at javax.mail.Service.connect(Service.java:176)
	at javax.mail.Service.connect(Service.java:125)
	at javax.mail.Transport.send0(Transport.java:194)
	at javax.mail.Transport.send(Transport.java:124)
	at sendemail.Sendemail.main(Sendemail.java:44)

public void setseqNo(int SeqNo)
   {
       seqNo = SeqNo;
   }

   public int getseqNo()
   {
       return seqNo;
   }

protected Node <E> insert (Node root,Node newNode)
  {
      if (root == null)
         root = newNode; 
      else
      {
        if((newNode.obj.getseqNo())<(root.obj.getseqNo())) // if first is less than second
            root.left = insert(root.left,newNode);
        else
            root.right = insert(root.right, newNode);    
      } 
      return root; 
  } 
    
  public void insertBST (E newObj)
  {
      Node temp = new Node (newObj);
      root = insert (root,temp);
  }

private static final java.text.Collator COLLATOR = java.text.Collator.getInstance();

private static final String[] NORM_STRINGS = new String['z' - 'a' + 1];
{
  COLLATOR.setStrength(Collator.PRIMARY);
  for (char b = 'a'; b <= 'z'; b++)
  {
      NORM_STRINGS[b - 'a'] = new String(new char[] { b });
  }
}