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.
How to Write Business Letter: Suppose you are writing a business letter for the very first time. You will ask yourself the question ‘how to write a business letter’. There is no need to scratch your head. All Business letters follow a fixed format. The answer to the question how to write a business letter is broadly classified into four categories.