Sending of Process Messages 
Use
All process messages are sent to their destinations by process management. This means that messages from external systems are first sent to process management, where they are processed in the same way as the messages created within the SAP system. The individual processing steps are:
Starting the send function
Checks and error handling
Transferring the message data to the destinations
NoteMessages that have been created for test purposes are monitored and checked against the predefined message categories in the same way as productive messages. However, they are neither sent nor checked for destination errors.
End of the note.