Could not connect to SMTP host smtp gmail com port 465 response -1

Question

I am getting this error when I am sending mails:

java.lang.RuntimeException: javax.mail.SendFailedException: Sending failed; nested exception is: class javax.mail.MessagingException: Could not connect to SMTP host: smtp.gmail.com, port: 465, response: -1

My code:

Properties props = new Properties();
props.put("mail.smtp.host", "smtp.gmail.com");
props.put("mail.smtp.starttls.enable","true");
props.put("mail.smtp.socketFactory.port", "465");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.port", "465");

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

try {

        Message message = new MimeMessage(session);
        message.setFrom(new InternetAddress("email"));
        message.setRecipients(Message.RecipientType.TO,
                        InternetAddress.parse(this.to));
        message.setSubject("Testing");
        message.setText("Hey, this is the testing email.");


        Transport.send(message);

Any help would be appreciated.