If you are writing to someone who has a doctorate or medical degree, use the abbreviated form: "Dr." However, for other titles, such as professor, judge, rabbi, etc., write out the full title and capitalize it. For example, your salutation in a letter to a judge would be, "Dear Judge Barnard." Or, if your correspondence was with a rabbi, you might write, "Dear Rabbi Williams."
Font Size: The traditional font size for a professional letter is 12. The font should be Times New Roman or Arial. However, if you are using letterhead, the letterhead may be in different font size and style. Font Style: There is no need to use different styles within a professional letter. Use a uniform font (book print font such as Times New Roman or Arial) and avoid underlining, italicizing, or bolding. However, if you are using letterhead, the letterhead may be in a different font style.