There are differences between the email open rate and clicks in email marketing campaigns, these are shown below:
Email "Opens" or "Open Rates" are statistics that track if a recipient had opened the email that they received. In order to track an open rate, the recipient must allow HTML to be displayed, as well as images to be displayed in the message when they view it. Many email clients do not automatically load images when a message is opened unless the recipient chooses to download and display them. This is done to protect the user from any harmful HTML that could be hiding within the email, and to save on data usage for mobile users.
When we cannot verify that an email has been opened, you will see entries in the "Delivered, Not Tracked" category of your reports. This means we sent the message successfully, but could not confirm that the email was opened by the recipient. As noted above, this is can often be due to email clients not automatically downloading the HTML code associated with the email.
Email "Clicks" or "Click-throughs" are shown in your reports when people are clicking on your links in your message content. They allow you to see how many people clicked on a link, and who those people are, to help you figure out how much traffic is being driven to the sites you are linking to. Tracking links are set up automatically when a message is saved so that all of the links in your content can be tracked. These links will show up in your email reports with the number of clicks and which recipient clicked them.
Emails sent in text-only format cannot be tracked as they do not contain the HTML information that tracks an email open rate.