Re: Is it possible to have an animated banner in an email? As a gif or video format
Jessica is spot on with GIFs. Videos, however, are a bit more tricky: It's possible to embed video in email with HTML 5, the problem is that 20-30% of email clients may have issues rendering the video (and proper fall back image) appropriately. It's much better to just add the thumbnail of the video with a big play button, and then embed the video on a landing page.
This really doesnt change the user experience much, but it gives the benefit of better tracking the clicks/views and assures that the majority of your audience won't have issues with playback.