app.js

/*!
 * Module dependencies 
 */
var express = require('express');
var http = require('http');
var path = require('path');

/*!
 * Application 
 */
var app = express();
app.set('port', process.env.PORT || 3000);
app.use(express.logger('dev'));
app.use(express.bodyParser());

// development only
if ('development' == app.get('env')) {
  app.use(express.errorHandler());
}

// Handle callbacks
app.post('/callback', function (req, res) {
  var data = req.body;
  // do something with the e-mail data
  res.end();
})

// start her up!
http.createServer(app).listen(app.get('port'), function(){
  console.log('Express server listening on port ' + app.get('port'));
});