An additional question would be - when the parcel is correctly address (and by correctly I mean also having a return address) I wonder how many make it back to the sender when they do not make it to the intended recipient.

I know missing parcels are a frustration, especially when a business relies havily on posting items, but when you consider the millions of parcels that make it to the destination each day out of the millions sent, the error factor is most likely quite small.

Anyone can make mistakes, my major gripe is that AP (and a lot of other ligistics company's) either refuse to reimburse you or make you jump through so many hoops to inititate a claim, that many just don't bother and write it off as a loss.