I'm sure you'll get more expert answers than mine, but my understanding is that the images, animations etc. are hosted elsewhere and are not actually sent with the email.
I presume you would design in html as you are doing but embed material in the page.
I have embedded You Tube material in a web page, but don't really know how it is done for an email - you would certainly need the material hosted somewhere.
Should I upgrade to Windows 10? 8 reasons why you should upgrade to Windows 10... and 2 why you…