Section 235(3) in The Orissa Municipal Corporation Act, 2003
(3)Such bills shall be sent by registered post with Acknowledgement Due or by Courier Agency to the person liable for payment of the property tax, not later than the 31st day of May of the year to which such property tax relates.Explanation. - "Courier Agency" shall mean any agency engaged in door to door delivery of time sensitive documents, utilizing the services of a person, either directly or indirectly, to carry such documents.