Hi everybody,
So, 'Litmus', a web app for testing emails and webpages across browsers and email clients, has a proprietary method that they claim is able to track not just opens, clicks, browsers, etc (standard with an embedded image and pass-through link tracking.)
What's unique is they claim that they are able to track what actions the end user took, how long the end user read it for, and if they deleted or forwarded the email. They claim they do this without JavaScript, and purely using embedded images. They claim that the method works across most major email clients.
What could they be doing to track this? Obviously, if they're doing it with third party applications that they don't control, whatever they are doing should be replicable.
I'm thinking that they realized that when an email client forwards or deletes an email, it 'opens' the email in a different way then normal, creating a unique user string on the server log of some kind? I'm grasping at strings, though.
anyone can help me in this regards