Such a bummer to have to submit this as i was hoping this was already a thing. We have a group that has several stages of proofing for their projects, and we are trying to avoid the proof owners having to constantly type out a message each time they send a proof. It seems logical that if you can create an automated workflow, you'd be able to create a custom message to go along with it. Even to create, as another user suggested, an automated custom message for each stage of a Workflow, would be a huge time saver. If this is an easy thing for the WF devs to do and for the PM's to add to our roadmap, man that would be great.