Deleting a user

We have a test instance of RT that we want to delete a user account from.
We are trying to alter the scrip for Autoreply on create, to have one reply
if the sending email is from our email domain, and another for all others
(our web server will not be available outside of our company, so we do not
want to have links to the tix and such for external users, but we do want
them to have the ability to send in tickets.)