[Mailman-Users] Filtering by file type - is it possible

[Howard Moscovitz]

We recently received a message from a masqueraded user. The included 
attachment was a file of type ".pif". It had a virus which fortunatley 
didn't do any harm.

Our list accepts attachments. Most come in as mimetype 
application/octet-stream. I can't filter out these 
application/octet-stream attachments, but I can identify the filetypes 
we can accept. Is there a way I can filter out messages that have 
attachments with filtypes I don't want?

I could set up a procmail recipe to weed out these messages. Can one use 
procmail with mailman? Any suggestions on how to do that?

Thanks much,
Howard