Send e-mail via GMail

Ilias TsagklisNovember 11th, 2012Last Updated: May 9th, 2013

0 63 2 minutes read

With this example we are going to see how to send an e-mail via GMail in a Java program. To do that you have to specify certain parameters about the SMTP host you have to use.

In short to send an email via GMail in a Java Application, one should follow these steps:

Set smtp properties using a Properties object.
Use put("mail.smtp.host", host) to set the smtp host.
Use put(“mail.smtp.port”, 25) to set the smtp port.
Use put("mail.debug", "true") if you want to recieve debugging messages.
Use put("mail.transport.protocol", "smtp") to set the email protocol.
Use put("mail.smtp.auth", "true") to set on the authentication.
Use put("mail.smtp.starttls.enable", "true") to set on the tls protocol.
Create e class tha extends Authenticator.
Override getPasswordAuthentication that returns a new PasswordAuthentication(username, password).
Use create a new Session.
Create a Message using a MimeMessage.
Set message source using setFrom(new InternetAddress(from)).
Set message recipients use setRecipients(Message.RecipientType.TO, address).
Use a Transport to send the email.
Use send to send the email.

Let’s see the code:

package com.javacodegeeks.snippets.enterprise;

import java.util.Date;
import java.util.Properties;

import javax.mail.Authenticator;
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 SendEMailViaGMail {

	private static final String username = "myusername";
	private static final String password = "mypassword";

	public static void main(String[] args) {

		String host = "smtp.gmail.com";
		String from = "myuser@gmail.com";
		String to = "myrecipient@mailprovider.com";

		// Set properties
		Properties props = new Properties();
		props.put("mail.smtp.host", host);
		props.put("mail.smtp.port", 25);
		props.put("mail.debug", "true");
		props.put("mail.transport.protocol", "smtp");
		props.put("mail.smtp.auth", "true");
		props.put("mail.smtp.starttls.enable", "true");

		// Get session with authenticator
		Session session = Session.getInstance(props, new GMailAuthenticator());

		try {

		    // Instantiate a message
		    Message msg = new MimeMessage(session);

		    // Set the FROM message
		    msg.setFrom(new InternetAddress(from));

		    // The recipients can be more than one so we use an array but you can
		    // use 'new InternetAddress(to)' for only one address.
		    InternetAddress[] address = {new InternetAddress(to)};
		    msg.setRecipients(Message.RecipientType.TO, address);

		    // Set the message subject and date we sent it.
		    msg.setSubject("Email from JavaMail test");
		    msg.setSentDate(new Date());

		    // Set message content
		    msg.setText("Java Code Geeks - Java Examples & Code Snippets");

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

		}
		catch (MessagingException mex) {
		    mex.printStackTrace();
		}

	}

	private static class GMailAuthenticator extends Authenticator {
		@Override
		protected PasswordAuthentication getPasswordAuthentication() {
			return new PasswordAuthentication(username, password);
		}
	}

}

This was an example on how to send e-mail via GMail.