This node.js app uses SendGrid's Inbound Parse API (Webhook) to pull an email's subject, which is then read out on a webpage. It uses this Mashape text-to-speech API to convert text to audio. It also uses Firebase to store data and do a callback to the webpage to play the audio.
You can go to this page to try the app.
You can find the tutorial explaining the basic components of the code here.
To configure the service, you need to copy config-sample.js to config.js with the required values:
config.mashape = {};
config.mashape.key = "Get your Mashape key from https://www.mashape.com/keys";
config.firebase = {};
config.firebase.hostname = "Create your Firebase from https://www.firebase.com/";
You also need to update public/index.html with your Firebase:
//TODO: Create your own Firebase at http://firebase.com/
var myDataRef = new Firebase('https://<your own firebase>.firebaseio.com/');