JavaMail 535 Authentication Error

JavaMail 535 Authentication Error

I'm trying to send an email via a program using the following bit of code:

  2. final String username = "xxxxx@xxxxx.com";
  3. final String password = "abc";
  4.         String to = "yyy@yyy.com";
  5.         String from = "xxxxx@xxxxx.com";
  6.         // SUBSTITUTE YOUR ISP'S MAIL SERVER HERE!
  7.         String host = "smtp.zoho.com";
  8.  
  9.         // Create properties, get Session
  10.         Properties props = new Properties();
  11.  
  12.         props.put("mail.smtp.auth", "true");
  13.         props.setProperty("mail.pop3.socketFactory.class", SSL_FACTORY);
  14.         props.setProperty("mail.smtp.socketFactory.class","javax.net.ssl.SSLSocketFactory");
  15.         props.setProperty("mail.smtp.socketFactory.fallback","false");
  16.         props.setProperty("mail.smtp.socketFactory.port","465"); //443 or 465
  17.         props.put("mail.smtp.startssl.enable", "true");
  18.         // If using static Transport.send(),
  19.         // need to specify which host to send it to
  20.         props.put("mail.smtp.host", host);
  21.         // To see what is going on behind the scene
  22.         props.put("mail.debug", "true");
  23.         Session session = Session.getInstance(props,
  24.           new javax.mail.Authenticator() {
  25.         protected PasswordAuthentication getPasswordAuthentication() {
  26.         return new PasswordAuthentication(username, password);
  27.         }
  28.           });
  29.  
  30.         try {
  31.             // Instantiate a message
  32.             Message msg = new MimeMessage(session);
  33.  
  34.             //Set message attributes
  35.             msg.setFrom(new InternetAddress(from));
  36.             InternetAddress[] address = {new InternetAddress(to)};
  37.             msg.setRecipients(Message.RecipientType.TO, address);
  38.             msg.setSubject("Test E-Mail through Java");
  39.             msg.setSentDate(new Date());
  40.  
  41.             // Set message content
  42.             msg.setText("This is a test of sending a " +
  43.                         "plain text e-mail through Java.\n" +
  44.                         "Here is line 2.");
  45.  
  46.             //Send the message
  47.             Transport.send(msg);
  48.         }
  49.         catch (MessagingException mex) {
  50.             // Prints all nested (chained) exceptions as well
  51.             mex.printStackTrace();
  52.         }
However, it fails with the following exception: 

javax.mail.AuthenticationFailedException: 535 Authentication Failed

at com.sun.mail.smtp.SMTPTransport$Authenticator.authenticate(SMTPTransport.java:892)
at com.sun.mail.smtp.SMTPTransport.authenticate(SMTPTransport.java:814)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:728)
at javax.mail.Service.connect(Service.java:386)
at javax.mail.Service.connect(Service.java:245)
at javax.mail.Service.connect(Service.java:194)
at javax.mail.Transport.send0(Transport.java:253)
at javax.mail.Transport.send(Transport.java:124)
at JavaMailTest.main(JavaMailTest.java:65)

Any ideas on what the cause might be?