There are programs that scour through the internet looking for email addresses, when they find one, it is sent to whatever company is collecting them and then that company either sends you junk mail (spam) or sells it to many other companys that will send you junk mail. Because it is mostly likely to be found by just a program, not a live person, the email address won't work because the program isn't smart enough (yet) to remove the NOSPAM from the email address to make it a real address.