[Mimedefang] Blocking outbound Office documents

[Kenneth Porter]

I got a message in the quarantine this week due to a wmz attachment. A bit 
of research indicates that it's a "Windows Media Skin", apparently some 
"active" gizmo inserted by Office when it sends email. In researching it I 
once again visited Jeff Goldberg's Netrants and re-read his rant on Office 
documents as email:

<http://www.goldmark.org/netrants/no-word/attach.html>

Section 1.6 on prior version information is particularly worrisome.

How do company admins here feel about letting Office documents escape one's 
company boundaries? Have you encountered undesirable "leakage" as a result 
of users using Word as an email program?

My company does contract assembly (among other things) for a partner and 
that includes updating and correcting assembly documentation, and 
exchanging schedule information, so we share a lot of these documents 
between companies. Are there best practices for doing this kind of exchange?