display filter in attachments

["Luis A. Florit" <mutt-users@xxxxxxxxxxxxxxxxxxxxxx>]

Dear Mutters,

    I use a couple of perl filters to destroy the
adds in messages, like the ones added by Yahoo
and other mailing lists, or virus scan programs.
They work perfect for me. They are called mail-to-filter
and mutt-display.pl, and I call them with

  set display_filter='mail-to-filter | mutt-display.pl'

in my .muttrc file.

    However, I realized that when I receive a 
message diggest (many messages in one, that appear
as separate 'message/rfc822' attachments), and I
try to see one attachment, the filter programs
are not called, and the adds are shown. I tried
to configure my .mailcap with:

message/rfc822; cat %s | mail-to-filter | mutt-display.pl ; copiousoutput

but that didn't make any difference.

    Why is this? How I call my filter programs from the
attachment section?

        Thanks for your time!

            Luis.