Sorry Guys, but it's been done a long time ago by (Score 2, Informative)

The firewall I use does exactly what this company is claiming their new product does. I've been running it for years. It's Open Source to boot. It's called messagewall, and I think it's great. My (other) mail server receives between 100 and 700 spams a day, out of which I actually receive 1 or 2. I like it because it rejects the mail if it is spam before the sending server can actually send it.

The down side, you have to load, compile, and build it. It's not too bad, even for a non programmer like me.

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