46.— (1) Postal packets and mail bags in the course of transmission by post shall be immune from examination, detention or seizure, except as provided under this Part or any other enactment.

(2) A universal postal service provider and employees and agents of a universal postal service provider shall be immune from prosecution for the possession, carrying or delivery of anything prohibited by virtue of any enactment which is contained in a postal packet in the course of transmission by post.