Such requests for multiple forwarding generally are hoaxes, but enough gullible people receive the letter so that it spreads pretty far and wastes a lot of people's time. It is your responsibility to check the contents of an email before you forward copies of it. Feel free to copy that textfile and use it in the same fashion if you wish. In fact, you're most likely to receive junk mail if you've been participating in a listserv or newsgroup. To protect themselves from reprisal, spam senders frequently use special techniques to remove their own email addresses from the email they send out.
Some spam messages end with instructions about how to get off the marketer's mailing list.
Those instructions are usually, but not always, reliable. There have been instances in which unscrupulous marketers used those messages as a way of confirming that an email address was accurate. So I'm not sure what is the best tactic to use against spam. If you just delete the message without replying to it, you might not get another from the same sender. Figure out where the email came from, and find the internet service provider who provided the mail service.