Unpublish as Trigger, not as action

Hi All,

I want to set up a trigger/action sequence so that when content of a certain type becomes unpublished, site administrators would receive a notification email. In triggers, you can use unsubscribe as the basis for an action, but not a trigger itself. Does anyone know how I would go about this?

Cheers

_{Edited by WorldFallz - moved to appropriate forum.}