Gmail question
 

Is there a way for a Gmail user to see if another Gmail user has opened a email?

Not that I am aware of and I typically stay on top of Gmail stuff.
Heck you can not even really embed a small image in a mail and wait to see if it gets a hit on your server, unless that have clicked the display images or always display images from this sender.

I Haven't seen this yet

Bummer,,,Thanks