To be able to process a message, an applicable document flow and its related setup must exist. The moment the applicable document flow and setup is checked, is defined by inbound messages process and outbound messages process.
If you exchange EDI messages with 3PL warehouses, in the search for the applicable document flow, the warehouse is the key. The document flow must have the account code 'Warehouse'. So, in this case, the origin is not used.
This diagram shows the document flow search process for 3PL warehouse EDI messages.