Dan, Thanks for the heads up on this.
I have been using the paypal label printing for postage and it puts the delivery confirmation on all the packages.
I have been getting a lot of strikes with delivery confirmation and have not been hit for postage due yet.
I guess that a good shot of bubble wrap needs to be put around the strikes.
The USPS web has the information.

http://www.usps.com/send/waystosendmail/extraservices/deliveryconfirmationservice.htm