The best thing about Microsofts new Intelligent Message Filtering add-on for Exchange Server isnt that its free—its that it really works. Of course, having the ultimate "nice price" makes choosing IMF almost a no-brainer.
I have been using IMF for several days—too early to really make a determination—but the early results have been excellent.
If the name doesnt ring a bell, IMF is the server version of the anti-spam technology built into Outlook 2003. An important limitation in Outlook is that the client software only works in "cached" mode, in which all your e-mail is downloaded to the client for filtering takes place.
Having to your download e-mail onto every machine you use seems to defeat the purpose of having an Exchange server, and certainly cripples Outlook Web Access. While Outlook 2003 could filter the incoming mail and provide a mostly spam-free desktop experience, the server itself remained spam city. Thus, OWA, which provides server access via any web browser, got a completely unfiltered view of the users inbox. With IMF, spam is filtered at the server, and OWA shows your filtered inbox—OWA has been rendered useful once again.
IMF was released last week at TechEd in San Diego. It didnt get nearly the attention it should have, which is part of the reason I am writing about it here. Based on my experience with the Outlook 2003 anti-spam technology, I was looking forward to installing the server version on my Exchange machine.
Over the weekend—Sunday night to be precise—I downloaded IMF from the Exchange 2003 Web site and installed it on my server. Actually, I first read the IMF Overview, which explains how the filtering works. I then downloaded the Deployment Guide, which explains how to use a single IMF installation for several Exchange mailbox servers in an enterprise environment.