What the importance of post office?

Post office is a most oldest & cheaper cost service provider in communication sector

It sends mail to people around the world.

FPO = Fleet post office for Navy personel. Apo = Army post office for Army personel

"Post office" is simply "Post," or "Postamt."

If you're just writing "post office," then no. But if it's a specific post office, yes. For example: "New York City Post Office."

Main Post office (Head Post Office) to Main Post Office (Head Post Office)

The compound noun 'post office' is a common noun as a general word for a local branch of any postal service. Examples: I can stop at the post office. The post office has shipping cartons. The noun 'post office' is a proper noun as part of the name of a specific post office; for example, Springfield Post Office 19064 or Jackson Post Office 45640. A proper noun is always capitalized.

The plural form of post office is post offices.

a mailman works in a post office

Depends which post office you are at.

Information about post office guide.

Go to the post office.

Will be like a Master post Office

Grand post office General Post Office (UK) pre 1975, now Post Office

spanish for post office is correos