java mail

import javax.mail.*; import javax.mail.internet.*; import javax.activation.*; import java.util.Properties; public class MailClient {

 public void sendMail(String mailServer, String from, String to,
                         String subject, String messageBody, String[] attachments)
                         throws MessagingException, AddressException
 {
     // Setup mail server
     Properties props = System.getProperties();
     props.put("mail.smtp.host", mailServer);

     // Get a mail session
     Session session = Session.getDefaultInstance(props, null);

     // Define a new mail message
     Message message = new MimeMessage(session);
     message.setFrom(new InternetAddress(from));
     message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
     message.setSubject(subject);

     // Create a message part to represent the body text
     BodyPart messageBodyPart = new MimeBodyPart();
     messageBodyPart.setText(messageBody);

     //use a MimeMultipart as we need to handle the file attachments
     Multipart multipart = new MimeMultipart();

     //add the message body to the mime message
     multipart.addBodyPart(messageBodyPart);

     // add any file attachments to the message
     addAtachments(attachments, multipart);

     // Put all message parts in the message
     message.setContent(multipart);

     // Send the message
     Transport.send(message);


 }

 protected void addAtachments(String[] attachments, Multipart multipart)
                 throws MessagingException, AddressException
 {
     for(int i = 0; i<= attachments.length -1; i++)
     {
         String filename = attachments[i];
         MimeBodyPart attachmentBodyPart = new MimeBodyPart();

         //use a JAF FileDataSource as it does MIME type detection
         DataSource source = new FileDataSource(filename);
         attachmentBodyPart.setDataHandler(new DataHandler(source));

         //assume that the filename you want to send is the same as the
         //actual file name - could alter this to remove the file path
         attachmentBodyPart.setFileName(filename);

         //add the attachment
         multipart.addBodyPart(attachmentBodyPart);
     }
 }

 public static void main(String[] args)
 {
     try
     {
         MailClient client = new MailClient();
         String server="smtp.gmail.com";
         String from="[email protected]";
         String to = "[email protected]";
         String subject="Test";
         String message="Testing";
         String[] filenames = {"c:/somefile.txt"};

         client.sendMail(server,from,to,subject,message,filenames);
     }
     catch(Exception e)
     {
         e.printStackTrace(System.out);
     }

 }

}

Hi..I got this code from a site and im getting the following errors while running.. com.sun.mail.smtp.SMTPSendFailedException: 530 5.7.0 Must issue a STARTTLS command first. 6sm6761125anx.12

    at com.sun.mail.smtp.SMTPTransport.issueSendCommand(SMTPTransport.java:1829)
    at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:1368)
    at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:886)
    at javax.mail.Transport.send0(Transport.java:191)
    at javax.mail.Transport.send(Transport.java:120)
    at MailClient.sendMail(MailClient.java:52)
    at MailClient.main(MailClient.java:90)

help me clear this error..send suggestions to mail

mail : [email protected]

Thanks.....