Here’s an outline of our setup. 

In “Status” on the admin page add a new status called “open-no-reply” that is of type “open”.

In “Notification (Event)” our auto-replies reply if the state is “open” but not if it is “open-no-reply”.

In “Postmaster Filter” we have a rule that says if the From address contains “lists.wsu.edu” (our email list server), set X-OTRS-State to “open-no-reply”.