It seems that those who send unsolicited email are not concerned about whether it is actually wanted or not. Sadly it's impossible to know beforehand whether any piece of email consititutes spam without actually reading it, but once you do know, there's now a way to prevent yourself ever receiving mail from that machine again. Hopefully if enough people do this, the spammers will understand that their mail is never seen, so the whole exercise becomes counter-productive and hopefully stops. It expects to run in a UNIX environment, but may work in other systems. A mail filtering program is also required, and you will need a text editor to alter the configuration files.
Installation is a three stage process.
First edit the ignore-spam program, and change the variables at the top of the script to suit your personal environment. In particular, you should change the password that people can use to contact you. The four files contain the following spam-hosts hostnames of sites that have sent you spam email, one per line. The file distributed with ignore-spam contains examples of sites known to send out spam. Use this file with extreme caution.