1. In India, the postal network is amongst the largest in the world. It not only handles parcels across the subcontinent but also circulates personal written communications. 2. These mails are circulated via an extensive network regulated through the air, water as well as land transport. 3.In order to facilitate quick delivery of mails, six mail channels have been introduced including - Rajdhani Channel, Metro Channel, Green Channel, Business Channel, Bulk Mail Channel and Periodical Channel.