Apparent authority is a concept used in agency law that refers to the situation that arises when a principal, such as a corporation, indicates to a third party that an officer or agent is authorized to act on its behalf and the third party relies in good faith upon such authority. (US Legal N.D.)
Defendant states he allowed Knutson "to handle all the mail” and “left to [Knutson's] discretion to open [the mail] and to do with it as he chose.” (FindLaw 2007)