Changing AutoReply Behaviour


I have a pool of individuals who are our cutomers and they email to a
certain email address configured with mailgate (thereby creating a new
ticket). I want them to get a confirmation email from RT so I like the
AutoReply functionality here.

Now, there are others who are not exactly our customers but nevertheless
shoot email to that email address, and their email may not be a request.
I’m not granting the right to create a ticket to Everybody group so
they get a message saying they couldn’t create a ticket.

Has anyone done something like this where our real customers get
confirmation emails but our not-exactly customers do not get that error