How to set-up a Reject-Mail

Hi,
     Sorry for asking this question, may be it has been posted before.

I would like to set-up in my procmail(procmailrc file), so that
if I recieve an e-mail from someone (say from user(_at_)somewhere),
and I would like to reject that mail, and send that mail back
automatically to that person.
     Is there anyway to do that.

     Thanks alot for the help

Sincerely,
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Jonny
     jonny(_at_)helix1(_dot_)eng(_dot_)ohio-state(_dot_)edu