I recieved an email this morning saying a book I mailed had been "lost".

But... According to the PBS delivery confirmation, it was deliever July 11th.  The reciever  never marked it, though.

I used printable postage, so I didn't lose a credit... but I did the reciever get another one?

How do I correct this?

The thing about delivery confirmation is that the postal working can scan it as delivered, but it's possible that they delivered it to the wrong address. When PBS marks an item lost, the requestor does get their credit back.

If you really want, you can PM the requestor and say something to the effect of "Hello! Did you or your neighbors happen to receive the book? My DC said it was delivered July 11 and I wanted to just check in with you about it."

It's possible they just forgot to mark it received (which they can still do and need to even if the book was really lost for a while & finally arrived).

And if the requestor can't locate it at all, they can visit this website: https://postalinspectors.uspis.gov/forms/MLNtRcvd.aspx
This asks the USPS to investigate into the matter and hopefully turn up the lost book.

This is what I have found out recenlty.  Even though DC marks it delivered it seems like it is the PO  not the person and it also doesn't guarantee that the book was delivered to the correct address.  It can also sit in the PO for a period of time as well or if it is a distribution point it could sit there as well.  It may be that they haven't rec'd the book or it may be that they forgot to mark it rec'd.... I would

PM the person and ask them if they rec'd the book because it was marked lost but delivery confirmation shows it was delivered to her PO - that you want to open an investigation with the USPS if they haven't rec'd it ....wait for a reply. 

As far as the credit - yes I got mine back...then the book showed up a week later and when I marked it rec'd in the transaction log the credit was taken away again.  You aren't impacted either way.

 Edited:   Jennifer beat me to this - so I agree with Jennifer :)

THey might also be on vacation-it is that time of year.