Today, a printed letter is usually reserved for important professional communications, such as recommendation letters, job cover letters, resignation letters, legal correspondence, and company communications. Since a letter is a formal mode of communication, you'll want to know how to write one that is professional.Today, a printed letter is usually reserved for important professional communications, such as recommendation letters, job cover letters, resignation letters, legal correspondence, and company communications. Since a letter is a formal mode of communication, you'll want to know how to write one that is professional.Today, a printed letter is usually r...