Send Scheduled Emails from Python and Flask with Twilio SendGrid

This tutorial demonstrates how to use SendGrid's email scheduling options in Python and Flask applications. It covers the requirements, creating a Flask project, configuring SendGrid, sending test emails, and scheduling an email using Unix timestamp units. The X-SMTPAPI custom header is used to pass additional sending instructions as a JSON blob. This technique can be useful for scheduling emails at specific times without needing to implement your own background scheduling.