law: Indian Post Office Act, 1898 
  34. Transmission by post of value-payable postal articles 
  The Central Government
  
  may, by notification in the Official Gazette, direct that, subject to the other
  
  provisions of this Act and to the payment of fees at such rates as may be fixed
  
  by the notification, a sum of money specified in writing at the time of posting
  
  by the sender of a postal article shall be recoverable on the delivery thereof
  
  from the addressee, and that the sum, so recovered, shall be paid to the
  
  sender.
  Provided that 34[the
  
  Central Government shall not] incur any liability in respect of the sum
  
  specified for recovery, unless and until that sum has been received from the
  
  addressee.
  Explanation.- Postal articles sent
  
  in accordance with the provisions of this section may be described as
  
  "value-payable" postal articles.