It DOES hit, and that's the problem.  Numerous false positive hits in headers searches due to detections in the content of the X-Ham-Report header.

Anyone know of a way to automatically remove a header, either with Mercury or within Pegasus Mail?  I'm using MercD to retrieve mail from hosted mailboxes and that host is running SpamAssassin which is adding an X-Ham-Report header which contains text content from the message.  It's making header searches very frustrating.  Here's an example:

X-Ham-Report: Spam detection software,
 running on the system "host215.hostmonster.com",
 has NOT identified this incoming email as spam.  The original message has
 been attached to this so you can view it or label similar future email.  If
 you have any questions,
 see root\@localhost for details.  Content preview:  Search Products | Trade
 Center | My Alibaba | ! Forgot Password? Inquiry about your product You got
 1 order inquiry notification from our customer about your product. Click the
 button below and login with your valid email to view the customer inquiry
 samples page. CLICK HERE Wishing you best of business, ...
 

If the content that is being found is part of the message, isn't this OK? Wouldn't the search results identify the same message anyway? Or, perhaps I misunderstand what you want to do.