通常商务交流中的书信书写格式分为四种，每一种都有其突出的地方，而选择用哪种格式则看写信人的爱好了。
Modified-Block Letter Format
In this format each typed element - except the date and the signature block - begins at the left-hand margin. The date may be backspaced from the right margin point to align at the right margin; it may be centered, or it may begin at the center. The most attractive placement of the date, however, may depend on the letterhead design.
这种格式下，书信的排版，除了日期和签名部分，都从左边空白处开始，没有空格，段段之间空行。日期可以放在最右边，也可以放在中间，自成一行。最吸引人的写日期的地方，其实应该根据书信抬头的设计而定。
Semi-Block Letter Format
This format resembles to the modified block in every other regard except that the paragraphs in the body of the letter are indented.
这种格式的排版，出了书信主体每段首行要空格以外，其他均类似于Modified-Block Letter.
Full-Block Letter Format
The full block format is illustrative of the trend toward simplicity and ease of use. All lines, including the date and the signature block, begin at the left margin. Paragraphs are always blocked.
This letter arrangement is more efficient than the modified block or the semi-modified block in that no extra time is required for paragraph indention or placement of the date and closing lines. In addition, many writers believe that the full-block arrangement provides an attractive, business-like appearance.
这种格式是写作者倾向于简单方便的一个证明。所有的段落，包括日期和签名都从左边开始，没有空格，段段之间通常空行。
这种排版比上面两种要更加有效，因为上面两种需要一定的时间来反映空格、日期以及结束语。另外，许多作者认为这种排版更能体现一种具有商业魅力的外表。
Simplified Letter Format
As in the full-block format, all lines in the simplified format begin at the left-hand margin. It leaves out the conventional salutation and complimentary close, invariably containing a subject line in lieu of the salutation indicating what the letter is about. Supporters of the simplified format argue that salutation and complimentary close contribute little to the message except for a waste of time. Others, however, are reluctant to omit the tonal qualities of the two components because they have been used routinely over years and readers expect them.
和上面一种格式一样，这种格式也是所有的段落都从居左。它省去了常规的称呼和信尾的客套话，但是要在本来该写称呼的地方增加一句表明信的内容的主题句。喜欢这种格式的人认为称呼和信尾客套话对信息本身来说没有什么意义，相反只能是浪费时间。但是也有另外一些人很不愿意省掉这两个部分因为他们已经象惯例一样用了很多年，而且读者也习惯了这种方式。