title: Add Overlay to Image in HTML EMail Compatible With Most Desktop and Web EMail Clients
body: <p>Is there a way in 2017 to display either an <em>image- or text-based overlay</em> over the main image inside an HTML email, so that it is <em>properly rendered by most of the current Desktop and Web email clients</em>: Outlook 2007+, Thunderbird, Mobile Clients, GMail, Outlook.com, Yahoo Mail, etc.?</p>
  
  <p>As an example, it could be a small play button rendering over the main image, that when clicked would take you to a video url.</p>