[Windflier]

I use gmail but accessed through imap and a client that isn’t going to execute code so I don’t see how this would work.

Sounds like you're ahead of the curve of the average gmail user, but someone more knowledgeable about these things will have to answer the tech end of your question.

[steve86]

I can see how the “opening the one pixel image” would work, but the system still would not know who opened the message. I could forward a message without reading it or clicking any images and someone else could be opening it.