Email service providers embed a 1 x 1 image, often referred to as a “tracking pixel”, at the bottom of your email. When a recipient opens the email a request is made to load the tracking pixel and your ESP can infer that the email has been opened.
Since open tracking requires an image to be embedded on the bottom of an email, it’s impossible to track opens for text only emails.
If your email service provider supports click tracking they will wrap your link. This typically transforms your URL into something much longer.
When a user clicks the link the ESP redirects them to the original URL and sends Sendwithus the click event so we can track it.
Having trouble with open and click tracking? Consult your ESPs documentation for more information: