The SAP Cloud Application Programming Model (CAP) is a framework for building enterprise-grade services and applications. It provides high abstraction for enterprise-grade features such as database modeling, localization, data privacy, authorization, and messaging. The CAP framework offers flexibility to include arbitrary JavaScript libraries in its lifecycle for all other service integrations. This tutorial demonstrates how to send and receive emails with a CAP application using the SendGrid JavaScript client and webhooks. It builds upon a well-known "hello-world-scenario" called the bookshop, which is a small CRUD web application that exposes records of a single entity: Books. The project accepts HTTP POST requests to listen for incoming orders, reducing the stock field value. With the help of Twilio SendGrid, it ensures shop managers get notified when the stock of a given book runs low and provides an easy way to order more books from suppliers.