title: com.sun.mail.smtp.SMTPSendFailedException: 530-5.5.1 Authentication Required
body: <p>I am trying to send an Email from my Java Application to any particular email address.
  I am using Java Mail API but Unfortunately i am getting SMTPSendFailedException error. Can any body tell me where i am doing a mistake. Here is my code</p>
  
  <pre><code>import java.util.*;
  
  import javax.mail.*;
  import javax.mail.internet.*;
  import javax.activation.*;
  
  //import SeconMail.Authenticator;
  
  public class SendMail
  {
  
     public static void main(String [] args)
     {    
  
        // Recipient's email ID needs to be mentioned.
        String to = "to@gmail.com";
  
        // Sender's email ID needs to be mentioned
        String from = "from@expertflow.com";
  
        // Assuming you are sending email from localhost
        String host = "smtp.gmail.com";
  
        // Get system properties
        Properties properties = System.getProperties();
  
        // Setup mail server
  
        properties.setProperty("mail.smtp.host", host);
  
  
        properties.put("mail.smtp.starttls.enable", "true");
  
        properties.put("mail.smtp.auth", "false");
        // Get the default Session object.
        Session session = Session.getDefaultInstance(properties);
        session.setDebug(true);
  
        try{
           // Create a default MimeMessage object.
           MimeMessage message = new MimeMessage(session);
  
           // Set From: header field of the header.
           message.setFrom(new InternetAddress(from));
  
           // Set To: header field of the header.
           message.addRecipient(Message.RecipientType.TO,
                                    new InternetAddress(to));
  
           // Set Subject: header field
           message.setSubject("This is the Subject Line!");
  
           // Now set the actual message
           message.setText("This is actual message");
  
           // Send message
           Transport.send(message);
           System.out.println("Sent message successfully....");
        }catch (MessagingException mex) {
           mex.printStackTrace();
        }
     }
  }
  </code></pre>