Yes, it's how to get rid of x10 ads. You can also use your HOSTS file to map different IPs to localhost (127.0.0.1) which will nuke a lot of garbage. Do a search of the BBS and you'll find the thread. One simple click and no more x10 popups.

None of this is SPAM however. SPAM is generally mail and news offtopic and mass postings of some advertising nature. Specifically, ninti was talking about UBE - Unsolicited Bulk Email. It costs your ISP money and it costs you money in the end. Not the same thing as sending junk mail through the post office either.

spamcop.net
http://spamassassin.taint.org

I'm probably going to install Spam Assassin on the colocated server one of my websites lives on. Then I'll use it as a forwarding gateway for all my mail. Should clean things up quite a bit.

Complain to your ISP or other mail provider if you get a lot of junk mail. They can institute all sorts of filters and use all sorts of human-tracked blocking lists to help with the problem. You might also consider a mail account at Spamcop or some other service. You can even go with a place that allows white-lists, so anyone sending you mail for the first time has to manually send it again with a confirmation code to get onto your accepted-list.

Bruno