> HTML tags (like RTF coding and UUencode coding, both of which I also
> suspected before reading your message citing the problematic headers) can
> show up in plain-text messages; on occasion they trip up the software of
> individual recipients, as I think happened here.

Without disputing Chuck's analysis, I have to say I don't understand its
relevance unless I have failed to grasp the nature of the problem.

As I understand it, the list (with keywords coded as sent to us, including
Attachments= no) is blocking attachments (including HTML, because Language=
nohtml is also coded) sent by anybody except one contributor, who is able to
send (at least) Word and PDF files as attachments. The sample headers were
for a message successfully sent with attachments by that subscriber, and
presumably distributed to everyone on the list whose email didn't block it.

Have I got the correct description of the problem?

In any case, I still don't see how it's happening. The only other data I can
think of that might be relevant is the MIME header for the attachment.

Hal Keen