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.
Beginning the Letter. Know the format: There are some business standards which need to be followed. One must use a common font to type a business letter. One must use indentation, paragraphs, margins etc. The text must be typed in black color only. Choose the Right Kind of Paper: One must print a letter in a letter sized paper. The standard size of the paper is A4.