Has anyone played around with HTML5 video inside an email and been unable to get the poster image to be displayed? On Apple Mail for desktop, it shows a blank white space with the controls. On iOS, it either shows a play button or controls against white space, depending on the version. The poster attribute is added with a correct link path, but does not show.

<video poster="IMG/video.jpg" width="560" height="315" controls autoplay muted loop src="https://d1cpur18144r7g.cloudfront.net/media/video/plae_solespace_osa_event.mp4">
<a href="">
<img src="IMG/video_play.gif" width="560" border="0" style="display:block;width:100%;max-width:560px;min-width:100px;height:auto;border:0;" />