ASP.NET Core Identity provides a built-in feature for sending emails as part of its account management, authentication, and authorization features. However, this feature is not enabled by default and requires manual configuration to send emails using Twilio SendGrid. The process involves setting up Sender Authentication with Single Sender Verification or Domain Authentication, creating a SendGrid API key, and implementing the IEmailSender interface in the application. To simplify the process, developers can use the SendGrid dependency injection NuGet package to inject an instance of ISendGridClient into the application. By following this tutorial, developers can send emails using Twilio SendGrid as part of their ASP.NET Core Identity applications.