Ian Blackburn

Spam filtering in Exchange 2003

I have tried various spam filters for my email, but the best I have used is in fact the one that comes with Outlook 2003.  However it was always a bit of a pain that this happens in the Outlook client rather than the server.  But that has just changed.  Microsoft have released the free Intelligent Message Filter for Exchange 2003 (http://www.microsoft.com/exchange/downloads/2003/imf/default.asp).  You install it on the server then configure it with two levels of filtering.  The first is to configure a level of spam confidence, above which you want to archive or delete messages directly on the server.  You then configure a second spam confidence level at which the Outlook 2003 client will treat the mail as spam.  I currently run the first level at 6 and the second at 3, and this seems to be a nice balance for me.  90% of spam is caught on the server, and the rest ends up in my junk mail folder in Outlook- with few errors.

To help you fine tune your settings there are a couple of useful tips I have found:

• Exposing SCL (Spam Confidence Level) in Outlook  - http://weblogs.asp.net/exchange/archive/2004/05/26/142607.aspx - the Exchange team weblog explains how to show the SCL in you Outlook SPam folder.  This makes it easier to work out the levels you set the IMF to.
• http://hellomate.typepad.com/exchange/2004/06/imf_archive_man.html - little asp web site you can install that will show you the spam that is archived on the server, and either delete or resubmit them.  Again this is useful while you are fine tuning your levels in IMF.
  

posted @ Saturday, July 03, 2004 10:26 AM