How to Send a Letter?

In the United States, letters are sent via the U.S. Postal Service, which provides dark blue mail boxes and post offices at which to send letters. The latest time of pickup is displayed on a small card on the receiving receptacles at the post office. Letters must have complete addresses and zip codes and a stamp representing the current postage rate. The post offices also provide post office boxes for those living in rural areas and cannot receive mail at home. Look here for more information: