Review: Postini Perimeter Manager

Perimeter Manager is a good choice for effective spam blocking when end users also need control over how aggressively various filters sort mail.

The Postini Perimeter Manager anti-spam service requires that all MX (Mail Exchange) records for an organizations domain be directed to Postinis operations center. Thus, as with FrontBridges TrueProtect, all mail is filtered before getting to an organizations e-mail servers and requires no hardware or software purchase.

Unlike TrueProtect, Postini Perimeter Manager does allow administrators to define spam management policies on a corporate, a group or an individual level. This pleased the WiscNet judges, but they had misgivings that e-mail would have to travel off WiscNets network. WiscNets desire to have all e-mail travel on its lines is a concern that most corporations do not share, and so we advise IT managers to put Postini high on their short list of anti-spam services.

Indeed, Postini Perimeter Managers techniques for filtering spam were among the best we saw during the eVal. Where Postini differs is that Perimeter Manager caters to users desire to twiddle with their spam settings.

Given the state of spam e-mail messages today —where nearly all are as obnoxious as they are unwanted—we can see the value in FrontBridges flush-it-down-the-toilet attitude.

During tests, we could dial down racially insensitive mail to nearly zero but allow special offers through. (Hey, sometimes people really do want to look at mortgage offers.) We were also able to import lists of approved senders and block others, which is a nice feature for consumers of special-interest newsletters that often look like spam to e-mail filters, including Postinis.

Perimeter Manager, like many other products in this review, scores e-mail messages after passing the message through several filtering engines to determine the likelihood that the message is spam. It became clear to eWEEK Labs and the WiscNet judges that this technique is an effective compromise that allows technology such as header and message analysis to catch the vast majority of spam without incurring a reputation for capturing good e-mail and sending it to the bad e-mail hopper.

We recommend that IT managers ask about the way anti-spam products protect against Internet-based mail attacks, including directory harvest attacks. Postini, for example, uses its Connection Manager feature to determine the characteristics of SMTP connections.

Senior Analyst Cameron Sturdevant can be reached at cameron_sturdevant@