By default we track email opens and clicks using the same industry-wide implementations:
How is Open tracking done:
An invisible Image is added to the email content. The image is unique per email sent. When the image is loaded we register an email open event.
Users are using an email client (mobile, browser or desktop applications) to read emails. Those email clients have the option to disable image loading.
This means that our open tracking will not work, when the option is enabled. The trend is to disable loading images by default, and only when user clicks to load images, then our tracking image will be loaded and open event generated.
Email Servers are also reading access to email content and some of them (like Gmail and Apple) are pre-loading the image, even before the user reads the email. This thing breaks our real open tracking, therefore we might even have false email open events.
Conclusion: Open tracking is not relevant anymore. With the latest trends of increasing privacy for users, those images are not relevant any more.
How is Click tracking done:
Any link from the content is replaced with another link that we own, that registers the click event and does the redirect to the original URL.
Problems with reporting
As described above, we can not rely on open tracking. There are so many email clients, email servers that behave differently, no solution including ours can do anything about this.
Depending on specific cases you might have situations like over 100% opens or less than the number of clicks. In theory this does not make sense (to have a click but not an open), but it’s possible because of the images loading.