law: Indian Post Office Act, 1898 
  62. Penalty for defiling or injuring post office
  
  letter-boxes
  Whoever places in or
  
  against any letter-box provided by the Post Office for the reception of postal
  
  articles any fire, match or light, any explosive, dangerous, filthy, noxious or
  
  deleterious substance, or any fluid, or commits a nuisance in or against any
  
  such letter-box, or does any thing likely to injure any such letter-box or its
  
  appurtenances or contents, shall be punishable with imprisonment for a term
  
  which may extend to one year, or with fine, or with both.