[Mimedefang] DoD finally bans HTML e-mail

[Kenneth Porter]

--On Monday, January 08, 2007 10:50 AM -0500 "David F. Skoll" 
<dfs at roaringpenguin.com> wrote:

> I would strongly suggest blocking mail that lacks a text/* part
> entirely.  We've seen some image spams where the top-level MIME type is
> image/gif.  It's very hard or impossible to create such messages with most
> MUAs; they need to be crafted specially.

This looks like it might make a good SpamAssassin rule. Has anyone run this 
against a corpus to see how it scores?