Well yes although this is true your accuracy goes out the door. The problem with clamd is that the built in mime parser is really bad and it also does not do a good job of unpacking attachments even if you have the flag set to scan mail.
We use MIMEDefang, which extracts attachments itself and can also pass the original message to clamd. That way you get the benefit of two MIME parsers (MD's and ClamAV's), each with its own quirks, looking for attachments to scan. Additionally, there are some attachment types ClamAV will extract that, when I last compared the two, MIME::Tools (which MD uses) wouldn't. (I think it was BinHex, but it might have been something else.) With the amount of invalid mime out there (i.e. there's no defined way to extract it, so each parser will attempt error recovery differently), it's worth the overlap.
-- Kelson Vibber SpeedGate Communications <www.speed.net>
