Parts of a Business Letter

Business Letters in the United States usually contain the following information (in this order):

Letterhead or sender's address
Date
Inside address
Salutation or Greeting
Letter body
Complimentary closing
Signature, printed name, and position of sender
In some situations, a business letter may also include the following optional information:

Reference (RE:)
Carbon Copy Recipients (CC:)
Enclosures (ENC:)
Reference Initials (of the typist)