Deploying Exchange Intelligent Message Filter

At COMDEX last November, Bill Gates spent a portion of his keynote address announcing a new product: Exchange Intelligent Message Filter (IMF). COMDEX might seem like an odd venue for an Exchange Server announcement until you consider that IMF is really a spam filter and that spam is a growing problem and annoyance to users, administrators, and pretty much everyone except the people who send it. After you know what IMF does, how it works, and how to deploy it, you'll realize that IMF might not solve your spam problem all by itself but can be a valuable adjunct to other spam-reduction measures.

IMF Requirements
IMF is implemented as an event sink that extends the behavior of the Exchange Server 2003 SMTP service. IMF runs only on Exchange 2003 because it requires some changes that Microsoft made to support the tagging of suspect messages with a spam confidence level (SCL)--more about that later. In a typical deployment, you put IMF on an Internet-facing bridgehead server so that it can scan incoming SMTP mail. Because IMF requires Exchange 2003, you can't put it on a standalone server as a front-end filter. The only other limitation is that IMF doesn't support Exchange clusters, but you probably aren't using clustered bridgeheads to receive mail from the Internet, so this limitation isn't likely to be a problem. . . .