law: Indian Post Office Act, 1898 
  54. Penalty for fraud in connection with official marks
  
  and for receipt of excess postage.
  Whoever, being an
  
  officer of the Post Office,-
  (a) fraudulently puts any
  
  wrong official mark on a postal article, or
  (b) fraudulently
  
  alters, removes or causes to disappear any official mark which is on a postal
  
  article, or
  (c) being entrusted
  
  with the delivery of any postal article, knowingly demands or receives any sum
  
  money in respect of the postage thereof which is not chargeable under this Act,
  
  shall be punishable with imprisonment for a term which may extend to two years,
  
  and shall also be punishable with fine.