I am facing one issue related to view the attachment in the "message" tab of the purchase order screen. When I go to ME23N and select the "Messages" tab, it shows me the processed output types. I select one processed output type and go to "Edit" tab and select "Display originals". I can find attachment for few POs where as for few POs, I dont find the attachment. What is the reason of not finding attachements in all the POs? What is the purpose of this "Display Original" tab in PO Message screen?