law: 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.