Is it feasible to include HTML templates in the body of the message scenario pattern?

Summary:

When I attempted to construct the message's body in HTML—that is, to tailor it to the client's theme, perhaps including their header, logo, and footer—I was not getting any email.

Debugging steps I followed:

I added an inner step with some sample text in the body and added that as the next method in my start (When: Final status = False Method) to make sure there was nothing wrong with the body. I then received the inner email. Does that imply that adding HTML to the message scenario's body is not possible?