| A firewall will stop "unusual" or "unsafe" traffic to a system, spam isnt unusual its a mail message so as with any other mail messages they will fly through a firewall without a problem.
What you really want is either a spam firewall such as a Baracuda or decent spam filtering either on the desktop or before the mail gets delivered to you using a service such as MessageLabs or BlackSpider, both do a great job of cleaning your mail before it gets near your mailbox.
Jen |