Email Spike
This too allows you to put a video into your email that can play (this would be an mp4, and have a backup animated gif so if the browser doesn't display in the browser). You can also create a slideshow that you create write there in the software. You can also make a YouTube gif. This is a 10 second gif inside the email.
You can also create a countdown timer that shows in your email. You pick the style of the timer, the end date, the font size, font style, and copy and paste some code into your email.
You still need to create great content to get people to open the email, but this looks pretty cool. As I write this it is $47 and the creators say this price could go up to $200 at any time. So here again, a  company that has a scarcity tool is using scarcity. Shocking. If that works for you, then maybe you should use it in your emails by purchasing email spike. before the price goes up.