Autoreply recipe

Hi, Promail Gurus:

I used following recipe to autoreply message sent to a group address (cssa...)
but it seems not work:

          :0 Whc: vacation.lock
          * !^To(_dot_)*cssa(_at_)cs(_dot_)ualberta(_dot_)ca
          | formail -rD 8192 vacation.cache

            :0 ehc         # if the name was not in the cache
            | (formail -rA"Precedence: junk" \
                 -A"X-Loop: tang(_at_)cs(_dot_)ualberta(_dot_)ca" ; \
                 cat $HOME/cssad/nnotice \
              ) | $SENDMAIL -oi -t


Anyone out there know what is wrong with this recipe and what I can do about it?
Thank you for your help

-- 
Jun Tang
Department of Computing Science
University of Alberta