Send a mail through core java by using Gmail authentication

In the current post, I am trying to explain how to send a mail through the core java program by using Gmail authentication. The below mentioned only one core program which will contain the source code of mail sender. In the below source you have to place your Gmail username, password and from address and to address.  

As we know mail.jar is not present in J2SE, we have to download externally and place it into CLASSPATH. Along with mail.jar download the below list of jars and add it into CLASSPATH to avoid compilation error.

• dsn-1.5.5.jar

• gimap-1.5.5.jar

• imap-1.5.5.jar

• javax.mail.jar

• javax.mail-api-1.5.5.jar

• logging-mailhandler-1.5.5.jar

• mailapi-1.5.5.jar

• pop3-1.5.5.jar

• smtp-1.5.5.jar

GoogleMail.java

import java.util.Properties;

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

public class GoogleMail {

 public static void main(String... args) {
  final String username = "username@gmail.com";
  final String password = "password";

  Properties prop = new Properties();
  prop.put("mail.smtp.auth", "true");
  prop.put("mail.smtp.starttls.enable", "true");
  prop.put("mail.smtp.host", "smtp.gmail.com");
  prop.put("mail.smtp.port", "587");

  Session session = Session.getInstance(prop,
    new javax.mail.Authenticator() {
     protected PasswordAuthentication getPasswordAuthentication() {
      return new PasswordAuthentication(username, password);
     }
    });

  try {

   Message finalMessage = new MimeMessage(session);
   finalMessage.setFrom(new InternetAddress("from@gmail.com"));
   finalMessage.setRecipients(Message.RecipientType.TO,
     InternetAddress.parse("to-mail@gmail.com"));
   finalMessage.setSubject("Testing Email");
   finalMessage.setText("Dear Crawler,"
     + "\n\n This mail your getting as part of testing, please ignore! ");

   Transport.send(finalMessage);

   System.out.println("COOOLLL....Successfully sent email to your TO address. Please verify it. :)");

  } catch (MessagingException e) {
   throw new RuntimeException(e);
  }
 }

}

Please clear if you have got any compilation errors and run the program to send an email. But, before running the program you make sure you have placed proper username, password, from address and to address.

Hurrreeeyyyyy………did you got an exception which is related to the Authentication. Now, you’re in the right way. You have to log in to your Gmail to modify authentication settings by clicking on this link.

                https://www.google.com/settings/security/lesssecureapps

When you will get login into your Gmail, it will show you the below image screen. Just you have to select the ‘Turn On’ radio button and logout from Gmail.

Then you run once again the GmailSender.java program to send an email. If there are no exceptions you are getting, you will get the below message on your console.

COOOLLL....Successfully sent email to your TO address. Please verify it. :)

If you got that message in your console, you login into the Gmail which you have placed into TO mail and verify you got the mail or not.