Thanks for the question. I've seen this once in another email newsletter, like I said it was an ASP function that my current server doesn't accept.
The newsletter has a link, labelled Forward To A Friend, to a form where you type in your friend's email address. The entered address sends a copy of the newsletter that it's a part of to this new email address. Kinda neat.
I still have the newsletter, I can forward it to you if you want to look at it.
Tony