Monitoring email delivery and open rates in a .NET application using Twilio SendGrid Webhooks is made possible by creating a new ASP.NET Core Web API project, installing the SendGrid NuGet package, configuring SendGrid in the application, implementing email sending functionality, setting up a webhook endpoint to capture event data from SendGrid, running the app and exposing it with Ngrok, enabling event webhooks in SendGrid, testing the integration, and saving logs for analytics. Twilio SendGrid's event webhooks are powerful tools that can help evaluate the success of email campaigns and make informed decisions upon accurate results.