old_contents: // used modules
  var express = require('express');
  var cors = require('cors');
  var nodemailer = require('nodemailer');
  var bodyParser = require('body-parser');
  
  // global vars
  var app = express();
  var port = process.env.PORT || 1111;
  // allowed domains
  var whitelist = [
    'https://grievoushead.github.io',
    'http://grievoushead.github.io',
    'http://localhost:4321'
  ];
  
  // email sending transport
  var transporter = nodemailer.createTransport({
    service: 'Gmail',
    auth: {
      user: process.env.EMAIL,
      pass: process.env.PASS
    }
  });
  
  // cors
  var corsOptions = {
    origin: function(origin, callback){
      var originIsWhitelisted = whitelist.indexOf(origin) !== -1;
      console.log('Is origin allowed: ' + originIsWhitelisted);
      callback(null, originIsWhitelisted);
    }
  };
  
  // routes
  app.get('/', function(req, res, next) {
    res.send('how are you doing?');
    res.end();
  });
  
  app.options('/:to', cors(corsOptions));
  
  app.put('/:to', cors(corsOptions), bodyParser.json(), function(req, res) {
  
    var to = req.params.to;
    var subject = req.body.subject;
    var message = req.body.message;
    var secret = req.get('whereTheQuestionsWhereTheAnswers');
  
    if (!to || !subject || !message || !secret || secret !== process.env.SECRET) {
      res.status(400);
      console.log('to: ' + to);
      console.log('subject: ' + subject);
      console.log('message: ' + message);
      console.log('secret: ' + secret);
      res.end();
      return;
    }
  
    var mailOptions = {
        from: 'Hop Hey ✔ <HopHey@gmail.com>',
        to: 'wbserg@gmail.com, ' + to,
        subject: subject,
        text: message,
    };
  
    transporter.sendMail(mailOptions, function(error, info){
        if(error){
            console.log(error);
        }else{
            console.log('Message sent: ' + info.response);
        }
    });
  
    res.status(200);
    res.end();
  });
  
  console.log('express server listenning on port: %d', port);
  // start app
  app.listen(port);
  
new_contents: // used modules
  var express = require('express');
  var cors = require('cors');
  var nodemailer = require('nodemailer');
  var bodyParser = require('body-parser');
  
  // global vars
  var app = express();
  var port = process.env.PORT || 1111;
  // allowed domains
  var whitelist = [
    'https://grievoushead.github.io',
    'http://grievoushead.github.io',
    'http://localhost:4321'
  ];
  
  // email sending transport
  var transporter = nodemailer.createTransport({
    service: 'Gmail',
    auth: {
      user: process.env.EMAIL,
      pass: process.env.PASS
    }
  });
  
  // cors
  var corsOptions = {
    origin: function(origin, callback){
      var originIsWhitelisted = whitelist.indexOf(origin) !== -1;
      console.log('Is origin allowed: ' + originIsWhitelisted);
      callback(null, originIsWhitelisted);
    }
  };
  
  // routes
  app.get('/', function(req, res, next) {
    res.send('how are you doing?');
    res.end();
  });
  
  app.options('/:to', cors(corsOptions));
  
  app.put('/:to', cors(corsOptions), bodyParser.json(), function(req, res) {
  
    var to = req.params.to;
    var subject = req.body.subject;
    var message = req.body.message;
    var secret = req.get('whereTheQuestionsWhereTheAnswers');
  
    if (!to || !subject || !message || !secret || secret !== process.env.SECRET) {
      res.status(400);
      console.log('to: ' + to);
      console.log('subject: ' + subject);
      console.log('message: ' + message);
      console.log('secret: ' + secret);
      res.end();
      return;
    }
  
    var mailOptions = {
        from: 'Hop Hey ✔ <HopHey@gmail.com>',
        to: 'wbserg@gmail.com, ' + to,
        subject: subject,
        html: message,
    };
  
    transporter.sendMail(mailOptions, function(error, info){
        if(error){
            console.log(error);
        }else{
            console.log('Message sent: ' + info.response);
        }
    });
  
    res.status(200);
    res.end();
  });
  
  console.log('express server listenning on port: %d', port);
  // start app
  app.listen(port);
  
subject: enable html body