Great email gateways are tough. Battle hardened. Darned near unbreakable.

So why not set that spam, virus and content filtering appliance outside your firewall? By diverting all that SMTP traffic elsewhere, you’d take some heat off the poor lunk.

Before you work yourself into a lather, take a gander at a couple of screenloads of firewall logs. What do you see? Legions of virus-driven zombie probes of ports: 9898, 5554, 65506, 1025, 1029. Read that: dabber, sasser, phatbot, blackjack and ICQNuke98.

As the network’s doorman, your firewall simply checks its list. Based on that, packets are either in or out: ftp in bagle out grokster out sasser out edonkey2000 out ssh in phatbot out…

On the other, the email appliance acts like hotel security gone wild. Each packet that comes its way gets the third degree, along with an enthusiastic cavity probe. Compared to the firewall, your gateway does slow, deliberative work.

By shoving it ahead of your firewall, you’ll turn a crackerjack detective into a really slow doorman that does detective work on those rare occasions when it has time. Message processing capacity will be sorely reduced.

So where should you place your email appliance? Don’t even ask. It’s a no brainer.