If you have a SBS 2003 server running Intelligent Message Filtering, and you're using ORDB as one of your Real Time Block lists, some time around January 7th, your SBS server may have stopped routing inbound faxes to an email recipient.  The official SBS Blog wrote this post on the issue a couple days ago, but we started experiencing the problem about a week ago, before we could find any information on it.

We resolved the problem by using the Custom Weighting feature in Exchange.  This is a feature that allows you to specify key words or phrases that if IMF finds in an email message, will cause it to allow the message through.  You can find this discussed about half way down the page here:  http://download.microsoft.com/download/f/b/5/fb5c54af-fe5c-48e9-be97-f9e8207325ab/Ex_2003_SP2_RelNotes.htm

We added a line like this:

<CustomWeightEntry Type="SUBJECT" Change="MIN" Text="FAX"/>

Admittedly, this isn't the best solution for the problem, but the custom weighting feature is still something that should be enabled on SBS if you're using IMF.  We likely won't remove the line, and we can quickly add more strings any time.