Thanks for the info, markupstart.
It seems like it's one damn thing after another.
Truth is, an occasional business associate of mine sent me a couple of emails with this crap in them. My first reaction is, it's none of anybody's damn business when or if I read their email. To hell with them. My second reaction, is, this is the spammer's best friend. It verifies active email addresses. My third and final reaction is, all email containing this link goes in the bit bucket without me even seeing it.
I do see that turning off image downloading will defeat the notification.
What new form of idiocy will be next?
If man was meant to fly, God would have given him a big brain and apposable thumbs.