https://github.com/leemunroe/responsive-html-email-template

https://www.smashingmagazine.com/2017/01/introduction-building-sending-html-email-for-web-developers/

https://www.smashingmagazine.com/2013/06/email-templates-web-designers-developers-pdf-odt-txt/ https://www.smashingmagazine.com/2010/01/design-and-build-an-email-newsletter-without-losing-your-mind/

Email Frameworks:

https://justjensen.co/reporting-data-102-auto-emailing-reports-with-python-mjml-and-gmail/