You have the answer in the FAQ
http://www.python.org/cgi-bin/faqw-mm.py?req=all#4.13
David Lamotte wrote:
> Hi,
>
> I am just getting started with Mailman (so please excuse my ignorance), but
> I cannot see where you can strip attachments from posts.
>
> What have I missed ?
>
> Thanks
>
Look at the FAQ:
http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq04.013.htp
Most of these viruses/attachments come in as MIME encoded, so you can
always use stripmime[1], or demime[2] to get that stuff off of the
message prior to submitting it to the list. You can go one step further