When your letter is to more than one person, write out all of their names separately, separating them with commas. For example, "Dear Mr. Hobbes, Ms. Luxe, and Mr. Hopman." For married couples, if one person in the couple has changed his or her name, you only need to use the last name once. For instance, "Dear Mr. and Mrs. Smith."
The best writers strive to achieve a style that is so clear that their messages cannot be misunderstood. One way to achieve a clear style is to minimize your use of the passive voice. Although the passive voice is sometimes necessary, often it not only makes your writing dull but also can be ambiguous or overly impersonal. Here’s an example of the same point stated in passive voice and in the active voice: PASSIVE: The net benefits of subsidiary divestiture were grossly overestimated. ACTIVE: The Global Finance Team grossly overestimated the net benefits of subsidiary divestiture.