Donna,

>When a particular individual sends a message with an attachment, it passes
through the list and everyone receives the attachment.
>
>No one else can send attachments to the list, the attachment shows in the
archives and everyone recieves the attachment.

Thanks for clarifying. I thought that was what was happening, but your
problem is sufficiently unusual that there was some uncertainty showing in
the discussion.

The next thing I'd like you to confirm is that the email header, of which
you already gave us a copy, is taken from one of the emails received, with
an attachment, from the list.

And the following step is get us the MIME descriptors for the various parts
of that message. I note the header contains the following:
   MIME-Version: 1.0
      :
   Content-Type: multipart/mixed; boundary="=_mixed 0058420A8025730C_="

With a multipart/mixed message, there should be several pieces beginning
something like this:

     =_mixed 0058420A8025730C_=
     Content-Type: text/plain;
      charset="us-ascii"
     Content-Transfer-Encoding: quoted-printable

and

     =_mixed 0058420A8025730C_=
     Content-Type: application/vnd.ms-excel;
      name="ar-1-0-comments.xls"
     Content-Transfer-Encoding: base64
     Content-Description: ar-1-0-comments.xls
     Content-Disposition: attachment;
      filename="ar-1-0-comments.xls"

Each should begin with the boundary string coded in the header. What follows
in each case is a MIME description of a part of the message. (The examples
above are drawn from something that went through my own list, except that I
have substituted the boundary string from your example in hopes of giving
you a clearer idea how it works.)

Email clients tend to come up with lots of different ways to code the same
items. (I just had to expand my own allowed-attachments list to permit
another variant.) I am hoping something in the MIME descriptors written by
that one individual's email client will provide us a clue as to why his get
through, and that someone on this list will recognize that clue when they
see it.

But I don't have a proposed explanation yet; this is still a fishing
expedition. If you no longer have source for the example you sent us
earlier, we'll take a different one (but then the accompanying headers for
that case would be useful).

Hal Keen