In a move that came as no surprise, Microsoft announced the availability of the Intelligent message filter for Exchange 2003, due to later this year. At this time, it's going to be available exclusively to customers enrolled in Software Assurance, one complimentary license for the Intelligent Messaging Filter for each Exchange server enrolled in SA.

While everyone hoped it would be free and included in Exchange 2003 SP1, I wasn't surprised by the announcement, as rumors last fall hinted that it would not be "free". While this news is a big disappointment to many sites using Exchange 2003 who are not enrolled in SA, there are a number of excellent third party anti-spam solutions available that may do a better job.

The Intelligent Message Filter is based on Microsoft SmartScreen Technology developed by Microsoft Research. Developed in part as an answer to the overwhelming amount of spam received by Hotmail subscribers, SmartScreen technology can distinguish between legitimate email messages and unsolicited commercial email or other junk email. The Intelligent Message Filter evaluates the contents of incoming mail for recognizable patterns and assigns the message a rating based on the probability that the message is unsolicited commercial email or junk email. The rating is stored in a database along with the message, and contains a message property called spam confidence level. This rating persists with the message when the message is sent to other servers running Exchange and even other user's Inboxes. However, since only Outlook 2003 and Exchange 2003 support the spam confidence level rating, older Outlook clients won't benefit from it.

The administrator determines how the Intelligent Message Filter handles email messages with various spam confidence level ratings. He can set a gateway threshold and take action on messages above the threshold or use the mailbox threshold. When the message has a higher rating than the gateway allows, it handles the message. When the rating is lower, the message is delivered to the mailbox and is moved to the Junk E-mail folder by Outlook 2003 (also using SmartScreen technology), if it exceeds the mailbox threshold.

Microsoft may call it SmartScreen technology, but they are not the only company using similar tactics to combat spam and I could just as easily be describing some of the features available in many of the anti-spam filters on the market, including those that use Bayesian filtering technology. The Intelligent Message Filter supports the use of Real-Time Black lists, global deny and accept lists, sender filtering, and inbound recipient filtering. Once again, these same features are found in all third party filters. The Intelligent Message Filter needs to be installed on Exchange 2003, while many third party solutions can be installed on Exchange or on a SMTP server at the edge of the network, removing spam (and viruses) from the email system before passing it on to the back-end Exchange server. If you don't qualify for the IMF or use an older version of Exchange, there are many anti-spam programs on the market to choose from. Visit http://www.slipstick.com/addins/content_control.htm for the list which includes several excellent applications available from Slipstick advertisers. You just might find a better filter that costs less than SA.

For more information about the Intelligent Message Filter for Exchange 2003, see http://www.microsoft.com/exchange/techinfo/security/imfoverview.asp

I received a message from Brian Kennemer, a Microsoft Project MVP, a couple of weeks ago. He explained how he uses Outlook 2003's Rules, colored Flags, Search folders, and the new Grouping feature to help manage the email he receives on several accounts.

Blue, Yellow, and Orange flags are added to messages by Rules Wizard, based on the email account they were sent through, and Green flags are added to messages sent to distribution lists. Brian then uses search folders to view the messages by grouped by the flag color and he can easily tell which account the messages arrived on. As he flags the messages complete, they disappear from his search folders, reducing the clutter and making it easier to see the messages that still need action.

Outlook 2003's junk email filter is built on the same SmartScreen technology used in the IMF and gets rid of the majority of the spam for most people. However, there is one problem that affects people who use Rules Wizard to move messages to different folders. Since Rules Wizard runs before the Junk E-mail filter, any spam meeting the conditions of the rules is moved to a folder, not placed in the Junk E-mail folder. This is a frequent complaint in the Outlook forums as many users check multiple POP3 accounts and use rules to move messages sent to each account to different folders. In many cases nearly all of the messages are spam and its difficult for the users to find the good messages.

By putting Brian's email management techniques to work, users could eliminate much of their spam and easily tell which account the email was sent to, without moving the messages to a separate folder. If you need your flags for other things or don't want your messages flagged, create Search folders using the account name as the criteria. If you prefer not to use Search folders, try creating custom views or use advanced find to view messages by accounts.