How Opens and Clicks Are Tracked in ListManager Print

Opens:
Opens are tracked by placing a 1x1 pixel image into each message. When the message is opened, assuming the images are loaded by the mail client, the 1x1 pixel is downloaded from ListManager. ListManager counts this as an open. As each image has a unique URL, ListManager is able to log which mailing and member the open was generated from.

Clicks:
URL tracking works by replacing the actual URL with a unique URL to the ListManager web interface. When someone clicks a link, ListManager receives the click, tracks it, looks up the destination link in its database and redirects the browser to the link that was inserted into the mailing.

An example of the unique URL in a mailing with tracking clicks and opens can look like this:

http://yourserver..net/db/62014/11770998/1.gif
Tracks opens

http://yourserver.net/t/62014/11770998/3087/78/
Tracks clicks

Tracking link parameters:
http://yourserver.net/t/mailingid/memberid/urlid/groupid/

The difference between tracking clicks and opens is the opens will not include an "Urlid" since it isn't tracking any URL links.