As I understand it, html can only be embedded statically. In other words, you’d have to somehow acquire and convert the HTML to something that would compatible to the user. You could not feasibly or easily show Salesforce data in the email in this way.

Here’s a few articles about it. 
https://www.lifewire.com/how-to-send-html-email-3468764
https://www.mailup.com/resources-mailup/strategy/strategies-techniques-and-best-practices/creating-a-good-html-email-message/

Have you considered using Conga Composer? It may be better suited for this. 

Thank you, we just got away from Drawloop though and use SF and Skuid to generate PDFs and Email them , but it doesn’t embed the Skuid page, just creates it as an attachment and sends it using an Email Template

Making PDFs with Skuid eh. How extensive is that solution? I’ve been asked to look into this.

Not terrible. Drawloop had gone down on us 4 times and was too slow. It took us a few months, but got it to work using DocuRaptor and Apex code. We replaced about 25 different PDFs in a few months.

DocuRaptor. Nothing comes up in google and appexchange. What’s this?

Sorry, misspelled it DocRaptor.  https://docraptor.com/

Awesome! How’d I miss this all these years? Great post you referred me to btw.
https://community.skuid.com/t/idea-page-to-print-page-to-pdf-page-to-email-page-to-content-actions

And you’ve been able to send emails using just docraptor and apex?

Yep. It works great, I messed up last post and deleted and forgot to repost, but looks like you got it!

I didn’t see it tho! could you repost? Sounds super useful!. Thanks in advance!