Business Letter Writing Guidelines. Here are guidelines for writing a business letter, so all your correspondence makes the best impression. Margins: Business letter margins should be about 1" all around. This gives your professional letter an uncluttered look. You should align your text to the left; this is how most documents are aligned, so it will make your letter readable. Letter Spacing: Leaving space in your letter creates a clear, uncluttered and easy to read look that the reader will appreciate. Your letter should be in block format: the entire letter should be aligned to the left and single_spaced except for a double space between paragraphs.
How do you know for sure whether or not to use a closing? One good test is to ask yourself whether this email is more akin to an instant message/text or a business letter. If you're giving your teammate a quick update on an ongoing project, a formal closing might not be necessary; if you're throwing your hat in the ring for a promotion, it definitely is required. When all else fails, and you're still not sure, err on the side of caution and include it. You'll never go wrong by being too polite and respectful.