Airmail remains the fastest way to send handwritten letters around the world. Airmail used to be classified separately by the U.S. Postal Service, but as of May 2007 it has been incorporated into First Class Mail International. It is more expensive to send letters by airmail than by slower transportation methods such as "shipping," due to the fuel cost involved and lower storage space on board.
Purchase an airmail envelope from the postal office. These are white envelopes with a colored border around the edge of the envelope.
Seal your letter in the airmail envelope and purchase an airmail stamp and etiquette (an adhesive label used to indicate that a letter is to be sent by airmail) from a cashier. Prices for international postage are noted on the U.S. Postal Service's website, usps.com.
Post your letter.