I have been going through my missing in mail transactions trying to track down books and one of the books says that it was delivered but the person who was supposed to receive it says that they didn't receive it so it is still showing that it is missing.  Is there anything that I can do because I can't file a Missing Mail form.

Theresa

The recipient could have a neighbor who accidently received the book by mistake.  That person could be on vaca or in the cold spell that keeps them in for now ( not going to deliver it to correct person til it's warmer?). 'Delivered' by PO means it got delivered to someone, not necessarily the correct address.  There are multiple threads here on PBS that talk about their 'delivered' book ending up at a neighbor's for a few days. 

If it's a recent missing book and you still have the receipt for it then perhaps the PO from which you sent it can put a tracer on it. I've done this and have had good luck in tracing the package/book and getting it to the correct person at the correct address. But this works only with recently sent books, not sure what time lapse the PO puts on tracing packages.