Sending transactional emails in PHP has been made easier with the use of Twilio SendGrid, a tool that ensures emails arrive successfully every time. The tutorial covers setting up a composer project, installing necessary dependencies, and creating code to send a transactional email using the Twilio SendGrid API key. With less than thirty lines of code, developers can now easily integrate transactional emails into their PHP applications, providing a better user experience and preventing spam filters from blocking their messages.