I've noticed on several occasions now that messages appear to
be getting corrupted in the archives for the listserv that I
help run.  I originally thought it might have to do with the
following header in a message sent to the list.

    Content-Type: text/plain; charset=iso-8859-1

I've since narrowed it down to some strange tags that are being
inserted before and after the body of the message by the sender's
email program.  Or at least this is I'm currently thinking is
the cause of the problem.

    <x-charset iso-8859-1>... Body of message</x-charset>

Here are 3 examples with the first two showing the corruption
and the last one not.

http://listserv.photonews.com/cgi-bin/wa?A2=ind0111&L=photopro&D=0&P=29641
http://listserv.photonews.com/cgi-bin/wa?A2=ind0111&L=photopro&D=0&P=29732
http://listserv.photonews.com/cgi-bin/wa?A2=ind0111&L=photopro&D=0&P=29820

Has anyone seen this before?  Am I on the right track?  I'm
trying to get ahold of the folks sending these messages to see
what email client they are using.  The only one to respond
definitively so far says that he is using DellNet's IE/Outlook
Express derivative.

Thanks.

-steve