[Mimedefang] New virus out, how do I confirm no errors?

[Fox, Randy]

A new virus came out today with an attachment gone.scr.  MIMEDefang has
stripped several of these as expected.  However, while working with the
users, it is evident that some got through and were then cleaned by the
virus scanner on our internal Exchange servers.  I've gone through the
maillogs for the day and see no indication that MIMEDefang had problems.  My
question is, what do I look for to see if there's been any real errors?  I
have DO_LOGGING turned off, should I permanently turn it back on?  I can
tell from the headers that MIMEDefang did 'touch' all these messages
(there's a X-Scanned-By: MIMEDefang 2.1 (www dot roaringpenguin dot com
slash mimedefang) header in all the messages).  

TIA,
Randy Fox