I mailed out a book and according to the USPS it was delivered on 1/31.  The received has yet to mark the book received.  I've sent them a gentle reminder asking them to do so, they still have not.

Also, not everyone as daily Internet access. I know, I know, a rarity, but it occurs.

Yeah, it is way to early to be stressing about the book not being marked received yet.  There are all kinds of scenarios here...if it was scanned DC'd on the evening of 1/31 it may not have been delivered to the mailbox until 2/1 and the person may not have been to their mailbox (PO box) yet today to pick up the mail...here at the post office the place where it is scanned is across town from where it is actually put in the box and if it is out in the country then it is marked at one place delivered to another before it goes out on the truck to be delivered to the house (a process that may take several days).  Keep in mind that mail is not delivered on Sunday so, personally I would give it at least 1 week and technically the book will not be considered "lost" until 26 days after it was mailed and I'm not sure but, I don't think anything can be done until that time.

I have a couple of books that I know are at the post office waiting for me, but we are snowed in and I can't go get them yet.  So, to the sender, they are there, but I won't mark them received (even though I know they are there, too) until I've been able to actually get them and make sure everything is okay. 

Also, their internet connection might be out because of weather. About two days ago, we lost our connection because of wind and it took all day for it be restored. 

I'm just curious.  If you use DC don't you get your credit immediately?  Why so antsy for receiver to mark it as such?  Obviously receiver needs to do so.  But it's not like you're desperate for the credit .  What am I missing?

Rebecca W.

Depends. If you buy DC at the post office (not through PBS) you won't get a credit assurance. If you use PBS DC, you get credit once a USPS scan comes through the PBS system. If you use PBS Postage (comes only with DC), you get instant credit once you mark the book mailed.