Sending automated mails -- Error -Not working

[bharath]

I am using java mail bean to send a email & I am receving this
error message

javax.mail.SendFailedException: Sending failed; nested exception is: javax.mail.SendFailedException: Invalid Addresses; nested exception is: javax.mail.SendFailedException: 553 sorry, Authentication failed or timed out. Please do get messages first to authenticate yourself.(#4.4.3)

I have used a mail bean the code of which is given below



import java.*;
import sun.net.smtp.SmtpClient;
import java.io.*;
import java.util.Date;

public class mailbean {

public void send (String to, String from, String sub, String mes) {
try{
Date dt = new Date();
SmtpClient client = new SmtpClient(" ");
client.from(from);
client.to(to);
PrintStream message = client.startMessage();
message.println("From: " + from);
message.println("To: " + to);
message.println("Sent: " + dt);
message.println("Subject:"+sub);
message.println();
message.println(mes);
message.println();
client.closeServer();
}
catch (IOException e){
System.out.println(e);
}
}

}

This code was working fine before. We have changes our mail server to rediff. When I am replacing the old smtp addrress with the new one I am getting the above error.
I would request someone of you to provide a solution for this .
Thanks a lot in advance for the solution


Now our mail server is

[Ben Souther]

bharath N M
Welcome to JavaRanch!

We're pleased to have you here with us in the JSP forum, but there
are a few rules that need to be followed, and one is that proper names are
required. Please take a look at the
JavaRanch Naming Policy and
adjust your display name to match it.

In particular, your display name must be a first and a last name separated by a space character, and must not be obviously fictitious. You may use initials for the first name but not the last.

You can change it here