Business writing varies from the conversational style often found in email messages to the more formal, legalistic style found in contracts. A style between these two extremes is appropriate for the majority of memos, emails, and letters. Writing that is too formal can alienate readers, and an attempt to be overly casual may come across as insincere or unprofessional. In business writing, as in all writing, you must know your audience.
If you’ve done that well, they’re going to be asking themselves “How can I make this happen?”, which you answer in the last section of your letter by proposing an action they can take. “Call me at 鴔) 555 to arrange an interview” or “Let’s meet next Thursday to discuss this proposal” or “Order your copy today”. Don’t leave the action for your recipient to figure out. I think a lot of time we lack the confidence to ask for the action we want, and we give ourselves an “out” by leaving it unsaid, hoping they’ll figure it out themselves.