The only service I used in PVG is a local run express delivery company, I can't remember the name, but it is within the departure hall.

If you ask the information desk, they will tell you where to find them (I think it's on the far right hand side, when you facing departure gates).

I believe they do courier service for large items as well. But they are really expensive! My 2-page letter to a Chinese destination cost me something like 150 RMB, and that was about 2/3 years ago.