Piping to Approve

[Rizulo <rizulof @ newschool . edu>]

I've seen a suggestion that a owner of a moderated list can send
( or pipe) the "Bounced for approval" message directly to
approve through his mailer. How is this done? Only from a Unix
mailer? I can't find anything in the archives or FAQs on how to
do this. I know how to include the "approved" password and
return the message to the list or run approved on the file.  But
this "piping" procedure seems much easier. 

Thanks,
Frank Rizulo