I can just imagine how you felt the second after you hit the send button, kind of frozen because you know there is not stopping it once that key has been hit.

I haven't done what you did, but I did have one of my emails forwarded on through several people to the person it was about. I work at a large university and one of the higher level administrators decided that it would be a good idea to have a model of a future academic building in our building so that students could "see the future". It was huge and after a couple of years (there were financial difficulties) I was sick and tired of it getting in the way. I wrote to someone I know and asked if she knew when we could get "the blasted thing out of the way so we can stop falling over it" and she, most unfortunately, passed it on to someone in that administrator's office, who passed it on to another support person, who then emailed it on to the administrator. He read through the entire thing, which was about 3 pages long at this point, and of course read my opinion of his pet project. He wrote to me, apologizing in a very sarcastic manner that his work was in my way. I went icy cold all over when I read it, almost stopped breathing from horror. Fortunately, I was too unimportant for him to think about any more so there were no awful repurcussions, though my boss was very unhappy. And he did have "the blasted" thing moved to another building where they would appreciate it!