Indian Postal Service.

The Department of Posts, trading as India Post, is a government-operated postal system in India; it is generally referred to within India as "the post office".

As of 31 March 2011 the Indian Postal Service had 1,54,866 post offices, of which 1,39,040 (89.78 percent) were in rural areas and 15,826 (10.22 percent) in urban areas. It had 25,464 departmental POs and 1,29,402 ED BPOs. At the time of independence there were 23,344 post offices, primarily in urban areas. The network has registered a sixfold growth since independence, with the expansion's focus primarily in rural areas. On average, a post office serves an area of 21.23 square kilometres (8.20 sq mi) and a population of 7,114; it is the most widely-distributed postal system in the world.  The large number is a result of a tradition of disparate postal systems, which were unified in the Indian Union after independence. Because of this far-flung reach and its presence in remote areas, the Indian postal service is also involved in other services (such as small-savings banking and financial services).

The postal service is under the Department of Posts, which is part of the Ministry of Communications and Information Technology of the Government of India. The apex body of the department is the Postal Service Board, consisting of a chair and six members. The six board members govern personnel, operations, technology, postal life insurance, human-resource development (HRD) and planning. The joint secretary and financial adviser is also a permanent invitee.

India has been divided into 22 postal circles, each circle headed by a chief postmaster general. Each circle is divided into regions, headed by a postmaster general and comprising field units known as divisions (headed by SSPOs and SPOs). These divisions are further divided into subdivisions, headed by ASPs and IPs. Other functional units (such as circle stamp depots, postal store depots and mail motor service) may exist in the circles and regions. In addition to the 22 circles, there is a base circle to provide postal services to the Armed Forces of India. The base circle is headed by a Director General, Army Postal Service (with a rank of major general).

Source : Wikipedia