Why can't I send emails in Nodejs, Ubuntu 16.04 using nodemailer.

I am using nodemailer to send mails, I was available to send mails through it in c9.io but I can’t in my droplet with Ubuntu 16.04, here is my actual code to send emails:

var sendEmail = function(subjectText, bodyText) {
  
  var nodemailer = require('nodemailer');

  var transporter = nodemailer.createTransport({
  	service: 'gmail',
  	port: 443,
  	options: {
  	  debug: true,
  	},
  	auth: {
  		user: 'altoqueMichael@gmail.com',
  		pass: '****'
  	}
  });
  
  // verify connection configuration
  transporter.verify(function(error, success) {
     if (error) {
          console.log(error);
     } else {
          console.log('Server is ready to take our messages');
     }
  });

  var mailOptions = {
  	from: 'altoqueMichael@gmail.com',
  	to: 'altoqueMichael@gmail.com',
  	subject: subjectText,
  	text: bodyText
  }

  transporter.sendMail(mailOptions, function(error, info) {
  	if(error) {
  		console.log('Email couldnt be sent.\n', error.response);
  	} else {
  		console.log('Email sent: ' + info.response);
  	}
  });
}

module.exports = {
  sendEmail: sendEmail
}

I have already tried shutting down the firewall, what can I do to make this work? Do you know another alternative to send mails via node’js in Digital Ocean servers?