Delivery: Signature Confirmation requires that the parcel be signed for when it arrives and means it will not be left at your doorstep. This is for added security and accountability. The parcel will arrive with your regular mail. If no one is home to sign for the package a notice will be left instructing the addressee to come to the post office to claim it. Unclaimed parcels will be held by the USPS until they are returned to sender.