The United States Postal Service has strict rules and regulations that a postal inspector needs to closely follow. If these rules are broken by any personnel of the said organization they can be heavily punished or penalized for their dereliction of duty. As per United States Postal Service norm, a postal inspector needs a search warrant based on probable cause for inspecting a particular first-class letter, parcel, or mail. Without proper authorization, an inspection will be considered illegal. The first class parcels and letter mails are protected against any form of inspection, investigation, or seizure. It can be noted that if a mail or a parcel is opened without a search warrant, it can be considered a direct violation of the Fourth Amendment of the American Constitution. If an individual or organization is found doing such activities they will be subjected to severe punishment under the Code of Laws of the United States of America.