Question

I am using the following program for sending email through Java. When I use this program, I am not getting any error. At that same time I am not getting out it, means the mail is being not sent. I am trying to send message to Gmail. Are these smtp correct or not?

props.put("mail.smtp.host", "smtp.gmail.com");

props.put("mail.smtp.port", "465");

package mail;

import java.util.Properties;

import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.Message.RecipientType;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class mail4 {

    private String from;
    private String to;
    private String subject;
    private String text;

    public mail4(String from, String to, String subject, String text){

        this.from = from;
        this.to = to;
        this.subject = subject;
        this.text = text;
    }

    public void send(){

        Properties props = new Properties();
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.port", "465");

        Session mailSession = Session.getDefaultInstance(props);
        Message simpleMessage = new MimeMessage(mailSession);

        InternetAddress fromAddress = null;
        InternetAddress toAddress = null;
        try {

            fromAddress = new InternetAddress(from);
            toAddress = new InternetAddress(to);
        } catch (AddressException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {

            simpleMessage.setFrom(fromAddress);
            simpleMessage.setRecipient(RecipientType.TO, toAddress);
            simpleMessage.setSubject(subject);
            simpleMessage.setText(text);
                        Transport.send(simpleMessage);


        } catch (MessagingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}




main class
***********

package mail;
public class mail5 {
public static void main(String[] args) {

        String from = "[e-mail]";
        String to = "[e-mail]";
        String subject = "Test";
        String message = "A test message";
        mail4 sendMail = new mail4(from, to, subject, message);
        sendMail.send();
    }
}

Answer 1

I think the port is 587 unless you’re using TLS (for which 465) is correct.
You’re not providing any authentication data:
Try this:

Session mailSession = Session.getDefaultInstance(props, 
  new javax.mail.Authenticator() {
    protected PasswordAuthentication getPasswordAuthentication() {
      return new PasswordAuthentication("xxxxxx", "xxxxxx");
    }
  }
 );