One could argue that a spam filter is not a firewall, but in practical terms (what is allowed on your computer from the outside, and what is not) it's close. I 've never used a spam filter before, but the time has come to install one. I have Windows XP Home Edition and use Outlook Express, version 6. I'll keep Outlook Express ! First, the spam filter has to be free or very cheap. My ISP does filter spam based on where it's sent from, but I receive spam with forged headers, suggesting that the emails come from within the ISP's domain. My ISP also scans the emails for viruses, and adds a spam score in header of the email. I'm not sure if there are any programs that can use that spam score, which would seem useful. Suggestions please ?