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.
Parts of Business Letter. A business letter will be more impressive if proper attention is given to each and every part of the business letter. There are 12 Parts of Business Letter. The Heading or Letterhead,Date, Reference, The Inside Address, Subject, Greeting, Body Paragraphs, Complimentary Close, Signature and Writer’s Identification, Enclosures , Copy Circulation, PostScript