app.js

// Required modules.
var cradle = require('cradle');
var util = require('util');
var http = require('http');

// Config.
var config = require('./config');

// Create a new HTTP server to accept Postmark POSTs.
http.createServer(function(req, res) {
	
	// Variable to hold chunked data from Postmark.
	var mailRaw = '';

	req.on('data', function(chunk) {
		mailRaw += chunk;
	});
	
	req.on('end', function() {

		// Get the JSON payload from Postmark.
		var mailJSON = JSON.parse(mailRaw);
		
		// Transform attachments (fairly cheesy, but seems to work).
		if(mailJSON.Attachments) {
			mailJSON._attachments = {};
			mailJSON.Attachments.forEach(function(attachment) {
				mailJSON._attachments[attachment.Name] = {
					content_type: attachment.ContentType,
					data: attachment.Content
				};
			});
			delete mailJSON.Attachments;
		}
		
		// Connect to CouchDB instance.
		var db = new (cradle.Connection)(config.couchHost, config.couchPort, {
			auth : {
				username : config.couchUserName,
				password : config.couchPassword
			}
		}).database(config.couchDatabase);
		
		// Insert new document.
		db.save(mailJSON.MessageID, mailJSON, function (err, res) {
		      if(err) {
		    	  util.puts('Error! Could not save mailRaw. ' + err.reason);
		      }
		      else {
		    	  util.puts('Saved document with id: ' + res.id);
		      }
		  });
		
		// Send an empty response.
		res.end();
	});

}).listen(config.serverPort);

config.js

module.exports = {
	serverPort: 8000,
	couchHost: '127.0.0.1',
	couchPort: 5984,
	couchUserName: '',
	couchPassword: '',
	couchDatabase: 'couchmail'
};