You can send emails from a Flask application using the Twilio SendGrid service by creating a new Python virtual environment, installing required packages, and configuring the Flask-Mail extension with your SendGrid API key. The email is sent through the `mail.send()` method, which requires proper configuration of the mail server, port, TLS, authentication, and username. A simple Flask application can be created to send emails, including a route example that integrates this functionality. If emails fail to be delivered, you can use the Twilio SendGrid dashboard to help debug what happened.