Under the United States Code, it is a federal offense for anyone other than the addressee to open a piece of mail. The law does allow for some exceptions, however.
Exceptions to the law include mail addressed to children under the age of 18 or individuals deemed legally incompetent. These letters or packages may be opened by the individuals' legal guardians. Mail addressed to a deceased individual may be opened by a family member or other individual assigned to handle the estate. In the case of a business, mail may be delivered to an employee. Law enforcement officials are allowed to open mail only if they have obtained a search warrant.