Of course, bouncing is of very little use as most of these people use a false reply-to address anyway, so all you really get is 4 times the messages as the servers bounce back and forth to each other. At work, I send all suspected spam messages to a spam user. This allows me to make sure that nobody screams that an important email got tagged. We have ~150 users and we recieve about 9000 spam messages a day. That is just unbelieveable to me. That averages to a spam message caught every 9.6 seconds. I add about 10-15 domains to my blacklist every day, and they keep coming up with new names.