Postini Perimeter Manager By Larry J. Seltzer November 11, 2003

• Product: Postini Perimeter Manager
• Direct Price: $15–$20 per user per year
• Company Info: Postini Inc., 888-584-3150, www.postini.com

Editor Rating:

Nobody has as rich a hosted antispam service as Postini. Postini Perimeter Manager is essentially a mail management operating system with a Web interface, including elaborate tools and facilities unmatched by any other product or service we tested.

Postini is available only as a hosted solution. The company has licensed its spam-scoring technology to Trend Micro, which implements it in its Spam Prevention Service, which we also tested, but this is a small part of the Postini service.

One standout feature is the ability to delegate capabilities to users and groups over and above global policies set for organizations. For example, an administrator would normally set a particular level of sensitivity to types of spam for the organization as a whole. Administrators can allow specific users and groups to modify their threshold levels. They can also allow or deny users access to the spam quarantine.

Wherever you look in Perimeter Manager, there's another capability beyond what you would expect in a simple antispam tool. You can set policies for attachment handling in the organization (for instance, blocking troublesome files, like PIF and SCR, which are usually associated with worms), and specify different size limits on attachments for different groups. You can also give specific management capabilities to help desk personnel in your organization, letting them grant or deny user privileges.

A set of APIs keeps your network directory in sync with the Postini directory; or you can use bulk import/export. There's even a server-side scripting language for performing bulk operations.

Unique to Postini's software is the scoring system. The administrator (or users, if the admin allows) sets a series of sensitivity levels for general spam, as well as subsets of spam types (Sexual Content, Make Money Fast, Commercial Offers, and Racist Content). Setting a sensitivity level higher or lower to one of the categories will increase or decrease the chances that such a message will be tagged as spam.

Perimeter Manager looks at a lot more than just the content. For instance, it checks for signs of falsified mail headers, and it performs heuristic analysis of the actual SMTP traffic coming from the server. Any of these other considerations could block a message before it ever gets to the content-based scoring system. Perimeter Manager also scans every message for viruses and worms, potentially saving money on such costs at the gateway.

Performance was right in line with the pack. Without tweaking, the package caught 84.9 percent of our spam messages. Its false-positive rate was a little high (1.4 percent), but these were all newsletters whose senders could be whitelisted, not messages from individuals.

If you're uncomfortable with a hosted solution, you'll need to look elsewhere. Similarly, if you're paranoid about false positives, you may be better off with BrightMail's package. But you can't beat Postini for sheer administrative