Open and click tracking are enabled by default for all Campaigns.
To allow for open tracking, at publishing time a special 1 x 1 pixel image is inserted at the bottom of your HTML content. As long as images are displayed by either the email client or your Contact, an open will be recorded.
Opens are not tracked in Plain-Text because images are not supported.
To allow for click-through tracking, the URLs in your content are replaced with special tracking links in both Plain Text and HTML content. This allows the system to track the number of times each link in your email is clicked. Each click goes to the our servers where the information is recorded. Users are then redirected to the URL defined in your content. This process is invisible to users.