An open tracking pixel is a transparent image placed in an email that can be used to track whether or not the email has been opened. email providers can insert a tiny, invisible image into each email message. When that email is opened by the recipient, the email provider can see that the image was accessed and can then record when and where the email was opened. This information can be used to track whether or not an email was actually read, as well as how long it took for the recipient to open it. Open tracking pixels are often used by marketing teams to measure the effectiveness of their email campaigns. By understanding how many people opened their emails, marketers can better assess which subject lines, call-to-actions, or other elements are most successful in getting people to engage with their messages. Additionally, open tracking pixels can be used to understand whether an email was forwarded or printed, which can also be helpful in gauging engagement. While open tracking pixels are a useful tool, they do have some privacy implications, as they allow email senders to track when and where an email is opened. For this reason, some email providers (including Gmail) block images from automatically loading by default, meaning that open tracking pixels will not work unless the recipient explicitly allows them. It's important to note that even if an email is opened with images disabled, the email provider may still be able to track when and where the email was opened, just not whether or not any images were viewed.