1. Structural Parts of Business Letters  
A business letter has eight structural parts: (a) the heading (letter-head ), (b) the date, (c) the inside address, (d) the salutation, (e) the body of the letter, (f) the complimentary close, (g) the signature (handwritten and then typed), and (h) any added notations.
1.1. Heading (信头)
The heading tells where the writer wrote the letter. Since most companies use stationary (文具) with printed letterhead: the company name, address, telephone, telex or fax numbers, and logo (the company symbol, 标识, 商标).
Sample:
Golden Trading Company Ltd.
34 Northern Avenue, New York, U.S.A.
Tel: 1234567 Telex: 2345667GBC Fax: 4455666
1.2. Date
The date tells when the writer wrote the letter. Under the printed letterhead, you can type the date in full, in the logical order of day, month, year. The position of the date depends on the style you use. When writing on blank paper, type the name of your firm, its address, and the date at the right or left margin, depending on the style you choose.
There are different ways of writing the date. The following two are recommended.
September 15, 1994
15 September 1994 (Note the Omission of the comma)
In British correspondence, the date is on the right and could be after the inside address.
There is a growing tendency to omit the –th, -rd, -nd and –st that follow the day.
Do not abbreviate or use figures for the month. Note:
Wrong:
Sept. 15, 1994
9/15 1994 or 15/9, 1994

Sample:
SKYVIEW ENTERPRISES
7111 Terrazo Place Sarasota, Fl 33031 (813)598 - 1026

January 20, 1995

1.3. The Inside Address (封内地址)
The inside address contains the name and the address of the addressee (收信人), the person or company you are writing to. It is on the left two spaces below the date line. If you know the name and title of the person, you should include them. In addressing an individual in a company, the inside address contains both the individual's name and that of the company. The address should be the same as the one on the envelope.
Courtesy titles are used in business letters. "Mr." "Ms." "Mrs." or a substitute form should never be omitted from the inside address. When writing to a woman always address her as she signs herself. It is considered correct to address a woman "Ms." unless she has signed herself "Mrs."
Esquire or Esq. may be used in addressing prominent attorneys (律师,商务或法律代理人) or other high ranking professional men who do not have other titles. "Esq." always follows the name, seperated from it by a comma. "Mr." does not precede the name when Esquire or Esq. is used. e. g.
Stone, Esq.
"Mr." or "Esq." is used in England for addressing a single man.
Other common titles include "Prof", "Dr", "Rev (reverend)", "Hon (honorable)" (used for senators, congressmen, ambassadors, governors, judges, mayors, and heads of government departments), etc.
"Messrs" (Plural form of Mr.) may be used in addressing a firm of men, or men and women, when the name includes a personal element. e.g. Messrs Marvin, Tobin and Smart.
Examples of the inside address:
(1) To an individual in a company
Mr. George F. Moore
Advertising Manager
Price & Patterson
234 Seventh Avenue
New York 5, New York
U.S.A.
(2) To an anonymous official in the company
Sales Manager
Office Systems Pty Ltd
124 Oak Street
Chatswood
NSW 2067
Australia
(3) To a company
Messrs, Kato & Co., Ltd
2 Nichome, Ginza Nishi
Chuo--ku, Tokyo
1.4. The Salutation
The salutation is the greeting to the reader. It should be typed flush (exactly on the same level) with the left margin, the first line two spaces below the last line of the inside address. The most common salutation consists of : Dear plus the recipient's name.
Here are some ways to write the salutation.
Dear Sirs/Gentlemen ---- to a company
Dear Sir ------to a man if you do not know his name
Dear Madam ------to a woman if you do not know her
Dear Mr Smith ------ to a man
Dear Mrs Smith ------ to a married woman
Dear Miss Smith ------ to an unmarried woman