You're right, it's not necessarily fraudulent, and there are cases like yours, or when someone's on vacation and uses their real home address as the return addr

You're right, it's not necessarily fraudulent, and there are cases like yours, or when someone's on vacation and uses their real home address as the return address. But there's no way to allow those while preventing abuse, so I can't imagine what good options they have other than to reject and trash those pieces of mail (since they have no way to return them). I guess they probably allow them and eat the losses due to abuse?