law: Indian Post Office Act, 1898 
  37. Power to make rules as to disposal of undelivered
  
  postal articles
  (1) The Central
  
  Government may make rules as to the disposal of postal articles which for any
  
  reason cannot be delivered (hereinafter referred to as "undelivered postal
  
  articles").
  (2) In particular and
  
  without prejudice to the generality of the foregoing power, such rules may- 
  (a) prescribe the period during which
  
  undelivered postal articles at a post office shall remain in that office; and
  (b) provide for the publication of lists of
  
  undelivered postal articles, or of any class of undelivered postal articles.
  (3) Every undelivered
  
  postal article, after being detained at a post office for the period prescribed
  
  by rule under the foregoing provisions of this section, shall be either
  
  forwarded, free of further charge, to the post office at which it was posted,
  
  for return to the sender, or sent to the office of the Post Master General.