When you load an image from a remote server it leaves an item in their activity logs (when you download the image, the IP address, your email client’s user agent, and a few other details).
If you make the URLs for the images unique, you can now attach an email send to a specific person reading that email, and you can see where and when they read it.
It’s been a security risk for a long long long time and only recently have email clients started dealing with it. Some will download the images remotely or proxy them for you, but I recommend disabling remote images in emails altogether.
Hold up, tracking pixels? What the fuck is that and how do I disable it.
When you load an image from a remote server it leaves an item in their activity logs (when you download the image, the IP address, your email client’s user agent, and a few other details).
If you make the URLs for the images unique, you can now attach an email send to a specific person reading that email, and you can see where and when they read it.
It’s been a security risk for a long long long time and only recently have email clients started dealing with it. Some will download the images remotely or proxy them for you, but I recommend disabling remote images in emails altogether.