It sounds like a perfect candidate for a Business Event that monitors a Generic Inquiry for $0 SO Invoices and has an Import Scenario as a subscriber that marks them as ‘Do Not Email’. I haven’t had much experience with these, but there are several write-ups by the community if you search for ‘business event import scenario’.
Have you considered a Sales Order type that doesn’t generate an Invoice? That’s how we’ve started to handle $0 Invoices...just not create them in the first place. You do have to update Inventory on the Process Shipment screen (if you’re using the Inventory module of course), but that can also be automated.
@jlowry40
Yes, I agree that business event is a way to fulfill your need.
Have you considered a Sales Order type that doesn’t generate an Invoice? That’s how we’ve started to handle $0 Invoices...just not create them in the first place. You do have to update Inventory on the Process Shipment screen (if you’re using the Inventory module of course), but that can also be automated.
So our SO Invoices are coming from the FS module and many times we don't know if the job is billable or not until afterward. So I imagine that a business event is the only option.