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.