This is a simple autoresponder for qmail.

Mail is sent to help@my-company.com. An automatically generated response
is sent back to the user with an address of "help@my-company.com".  You
can set the envelope sender to an empty string.  However, some programs
will parse the message for the "From:"  field and send an autoresponse
back to it.  It is received at your autoresponder, and you now have a mail
loop.

This autoresponder also catches some other simple situations such as mail
from a mailer-daemon, empty envelope sender, bulk precedence headers, etc.