Here’s a propsed way of handling this:
1. Create an Orchestration that receives the messages from the various vendors
2. Use a Correlation Set to identify the vendor for a particular message and publish the messages to the MsgBox
3. Create an Orchestration for each Vendor that receives messages directly from the MsgBox based on the Initialized Correlation Set
4. Translate the vendor messages into a common format and publish to the MsgBox
5. Create a Send Port that sends messages of the common format