Consider the daily life of whomever you’re sending a letter to _how many other things might they have on their mind when they read your letter. Maybe they have a meeting in five minutes. Maybe yours is one of 200 letters they have to wade through. Maybe it’s the end of the day and they’re worn out. Giving them a concrete action to take makes it all the more likely that it will “stick” _ they’ll add it to their todo list or their calendar, they’ll pick up the phone, they’ll check out your website, or they’ll respond.
Sometimes a person's gender is unclear from a name _ names like "Corey" or "Blake," are both common women's and men's names. If that is the case, do some investigating to determine gender from searching on LinkedIn or a company website. But if it remains ambiguous, simply write out the person's full name, dropping the title. For example, "Dear Corey Meyer."