Stamping envelopes is quite a tedious task in the postal services. Human errors and inefficiencies are among the problems related to this service. Most of the countries around the world perform almost all the postal operations manually. This includes manual envelop sorting and stamping.Having automated process to increase the efficiency in envelop sorting and stamping will truly increase the efficiency in the postal service.This paper focuses on a stamping machine which is fully automated, thereby requiring minimal human interaction. The essential part of the work is to design and implement a mechanical system for the stamping process. The major challenge was to produce such an automated stamping machine with low cost and minimal energy consumption, while meeting the requirement of the end users. A conceptual design has been developed, and a prototype has been built. The implemented system is able to detect envelopes and then perform the stamping on the envelope. Image processing techniques play a key role in this project. The stamping is given on top of the stamp which is pasted on the envelope. Statistics show that the functionality of the prototype is satisfactory. Hence, this project successfully converts the stamping process from a manual system to an automated system.