Contact Information: The first section of your letter should include your contact information and the contact information of the person you are writing, too. Also, include the date you are writing at the top of your letter. Letter Salutation: Unless you know the reader well and typically address them by their first name, you should include the person's personal title and full name in the salutation (i.e., "Dear Mr. James Franklin"). If you are unsure of the reader's name, include his or her title (i.e., "Dear Executive of Marketing"). If you are unsure of the reader's gender, simply state their full name and avoid the personal title (i.e., "Dear Jamie Smith"). If you are unsure of the reader's gender, name, and title, simply write, "To Whom It May Concern." Leave one line blank after the salutation.
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.