Indian Post Office Act, 1898
38. Disposal of undelivered postal articles at office of Post Master General
(1) Every postal article received at the office of the Post Master General under sub-section (3) of section 37 shall be dealt with as follows:-
(a) if practicable, it shall be redirected and forwarded by post to the addressee; or,
(b) if it cannot be redirected and forwarded as aforesaid, it shall be opened by some officer, appointed by the Post Master General in this behalf and bound to secrecy, in order to ascertain the name and address of the sender.
(2) If the name and address of the sender are so ascertained, it shall be returned by post to the sender, free of further charge or subject to such further charge as the Central Government may by rule, direct.