recently i am seeing certain images still loaded, whereas in the past none loaded. i haven’t investigated what is different about these images yet, though. anyone else observe similar?
You can embed the image inside the actual multi-part message, and it will be shown without accessing network. It is usually used for logos, signatures and the such and, afaik, can't be used for tracking mail opening.
Could be images with image data included in the email, that don't need to load remotely.