The tutorial covers building a web-based email client in Laravel PHP using Twilio SendGrid. The prerequisites include basic knowledge of Laravel, installation of Laravel and MySQL, setup of a SendGrid account, and configuration of the environment variables for the application. The tutorial then guides through setting up the database, seeding the users table, creating a controller class to handle sending emails, building the view with a form for users to fill out, updating the routes, and testing the application. The final result is an email client that allows users to send custom emails to multiple recipients using the Twilio SendGrid SDK.