This example shows how to establish a connection to an SSL-enabled POP3 email server and send a simple (text only) email.

    // Configure mail provider
    Properties props = new Properties();
    props.put("mail.smtp.host", "smtp.mymailprovider.com");
    props.put("mail.pop3.host", "pop3.mymailprovider.com");
    // Enable SSL
    props.put("mail.pop3.ssl.enable", "true");
    props.put("mail.smtp.starttls.enable", "true");

    // Enable SMTP Authentication
    props.put("mail.smtp.auth","true");

    Authenticator auth = new PasswordAuthentication("user", "password");
    Session session = Session.getDefaultInstance(props, auth);

    // Get the store for authentication
    final Store store;
    try {
        store = session.getStore("pop3");
    } catch (NoSuchProviderException e) {
        throw new IllegalStateException(e);
    }

    try {
        store.connect();
    } catch (AuthenticationFailedException | MessagingException e) {
        throw new IllegalStateException(e);
    }
    
    try {
      // Setting up the mail
      InternetAddress from = new InternetAddress("[email protected]");
      InternetAddress to = new InternetAddress("[email protected]");

      MimeMessage message = new MimeMessage(session);
      message.setFrom(from);
      message.addRecipient(Message.RecipientType.TO, to);

      message.setSubject("Test Subject");
      message.setText("Hi, I'm a Mail sent with Java Mail API.");

      // Send the mail
      Transport.send(message);
    } catch (AddressException | MessagingException e)
        throw new IllegalStateException(e);
    } 

Caveats:

• Various details have been hardwired into the code above for illustration purposes.
• The exception handling is NOT examplary. The IllegalStateException is a bad choice, for a start.
• No attempt has been made to handle resources correctly.

public class GoogleMailTest {

    GoogleMailTest() {

    }

    public static void Send(final String username, final String password, String recipientEmail, String title, String message) throws AddressException, MessagingException {
        GoogleMailTest.Send(username, password, recipientEmail, "", title, message);
    }

    public static void Send(final String username, final String password, String recipientEmail, String ccEmail, String title, String message) throws AddressException, MessagingException {
        Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
        final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
        // Get a Properties object
        Properties props = System.getProperties();
        props.setProperty("mail.smtps.host", "smtp.gmail.com");
        props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
        props.setProperty("mail.smtp.socketFactory.fallback", "false");
        props.setProperty("mail.smtp.port", "465");
        props.put("mail.debug", "true");
        props.setProperty("mail.smtp.socketFactory.port", "465");
        props.setProperty("mail.smtps.auth", "true");
        props.put("mail.smtps.quitwait", "false");
        Session session = Session.getInstance(props, null);
        // -- Create a new message --
        final MimeMessage msg = new MimeMessage(session);
        // -- Set the FROM and TO fields --
        msg.setFrom(new InternetAddress(username));
        msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipientEmail, false));
        JOptionPane.showMessageDialog(null, msg.getSize());
        if (ccEmail.length() > 0) {
            msg.setRecipients(Message.RecipientType.CC, InternetAddress.parse(ccEmail, false));
        }
        msg.setSubject(title);
        msg.setText(message);
        msg.setSentDate(new Date());
        SMTPTransport t = (SMTPTransport) session.getTransport("smtps");
        t.connect("smtp.gmail.com", username, password);
        t.sendMessage(msg, msg.getAllRecipients());
        t.close();
    }
    //    And use this code in any class, I'm using it in the same class in main method
    public static void main(String[] args) {
        String senderMail = "[email protected]"; //sender mail id
        String password = "769inzimam-9771"; // sender mail password here
        String toMail = "[email protected]"; // recepient  mail id here
        String cc = ""; // cc mail id here
        String title = "Java mail test"; // Subject of the mail
        String msg = "Message here"; // message to be sent

        GoogleMailTest gmt = new GoogleMailTest();

        try {
            if (cc.isEmpty()) {
                GoogleMailTest.Send(senderMail, password, toMail, title, msg);
            } else {
                GoogleMailTest.Send(senderMail, password, toMail, cc, title, msg);
            }
        } catch (MessagingException ex) {
            Logger.getLogger(GoogleMailTest.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}

You can use the same Example above Send Simple Mail with a little modification. Use msg.setContent() instead of msg.setText() and use content type html as text/html.

check this

msg.setContent(message, "text/html; charset=utf-8");

instead of

msg.setText(message);