Fixed

Tutorial: CSS Fixed Positioning in Interactive Email

This article shows off a fun example that we created and shows how you
can create your own interactive email that takes advantage of fixed
positioning.

What You Need to Know about CSS Fixed Positioning in Email

One of the key features of modern webkit based email clients is the
support for more sophisticated capabilities in email design such as CSS animations and interactivity in email.
Animations and interactivity commonly utilize CSS positioning to move
elements within the email.

This article will show you what can be
achieved with fixed positioning.