IMF Tricks
I was a little late in implementing IMF on my Exchange server, but did so recently. Here are three things I had to do to help me manage and control the spam that IMF was catching:
The first trick I discovered was that I needed a way to monitor the spam that was being caught by IMF. So I implemented the Exchange IMF Archive Manager: http://hellomate.typepad.com/exchange/2004/06/imf_archive_man.html
This allows me to pull up via a web browser and view all the emails quarantined by IMF, and dedice whether to delete them or resubmit them to the intended recipient (false positives).
But I kept finding that IMF was trapping emails that I did not want to be considered spam. So, the second trick was to implement the Custom Weighting Feature of IMF:
http://www.msexchange.org/tutorials/Intelligent-Message-Filter-version-2-IMF-v2.html
This allows me to tell IMF to adjust the weight assigned to an email based on specific content. This is done via anXML file that can be created with Notepad. Thus, I can tell it that any email that contains the words "SBS2003" should not bwe flagged as spam, or have it's weight adjusted.
But that still was not enough - as I wanted to be able to tell IMF to filter or not filter emails based on recipient(s). And lo and behold, here comes KB article 912587 to the rescue:
http://support.microsoft.com/Default.aspx?id=912587
Simply request the free hotfix from Microsoft, install it onto your server, and create the required registry key (for either an exclusive or inclusive list).
Hope this helps someone!