I don't really understand how this works. Does it just load an image from the unsendit server as the content of the email, which is re-generated on their servers?<p>I can't imagine how it would work otherwise.
here is a (fairly bad quality) video of how it works <a href="https://www.youtube.com/watch?v=sLYYh_fuCE8" rel="nofollow">https://www.youtube.com/watch?v=sLYYh_fuCE8</a>