Look for a Web security gateway that provides bidirectional traffic protection. The solution should protect enterprises from malware, data leakage and Internet misuse, while ensuring policy enforcement, regulatory compliance and a productive application environment. And make sure the appliance continually learns about emerging Internet threats through the vendor's own global network of intelligent devices.

You should also select a secure messaging gateway that provides security across multiple messaging protocols, including e-mail, instant messaging and Web mail. The gateway should leverage the vendor's own global network of intelligent devices to proactively uncover spam, phishing attacks, DDoS (distributed denial of service), viruses, zombies and Trojans.

Finally, choose a network gateway security solution for firewall and application-layer protection. The gateway should provide secure network access, protect Internet-facing applications, block viruses, spyware and spam, and create a forensic-quality audit trail for regulatory compliance and reporting.

Some pundits may be tempted to roll all three of these security gateways into a single "God box." But as you start to roll all capabilities into a single box, performance can lag. An e-mail gateway, for instance, is store-and-forward and doesn't need to offer subsecond response time. People won't notice if an e-mail's delivery lags for 30 seconds or longer. A Web gateway appliance, on the other hand, may require nearly real-time performance.

Practical experience and satisfied customers assert that the best solutions-oriented approach is to leverage Web gateway security appliances, messaging gateway security appliances and network gateway security appliances in tandem for multilayer security.

And remember, as you scan the market for options, be sure to investigate the financial health, stability and potential for the growth of each company.

Interview appliance vendors much in the way you would interview a job candidate, potential business partner or prospective college for your kids.

• Do they have financial staying power?
• How many engineers and PhDs do they have in order to keep up with rapidly evolving security threats?
• Who are their partners within the IT ecosystem? (Then, talk to those partners)
• Who are their existing customers? (Talk to a few)
• How do their systems snap together?

Just remember, with a little foresight and these questions, you won't make a decision you'll regret later on.

Daniel Ryan is president and chief operating officer of Secure Computing Corp.

Editor's note: Caveat columns are written by vendors knowledgeable about the topic presented. However, the vendors often have a stake in the technologies used to solve the problems discussed. Caveat emptor!