It is best practice with emails to work with the lowest common denominator and keep emails simple. Any and all interactivity with in emails should be limited to CTAs, Click throughs to a microsite, landing page, website, purchase site, sign up page etc. We always want the ability to measure and track reader engagement. Email is not an experience it is a messenger.
The Desire for Email Interactivity
Anchor Tags have no place in emails, anchors serve the purpose of keeping a person on a web page by jumping to content simple and user friendly. Long form emails lose effectiveness when they become novels or websites thus if content NEEDS to be jumped to a simple link out of email to a related page and the content specified is the appropriate action.
Animation GIFS may capture attention but still need to stay simple.
Responsive Emails emails can not be responsive. We build for mobile first as the base then from there look at our target audiences and where they are opening their emails to know what is most important in terms of laying out content.