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.
Closing the Letter. Choose a Closing: One must use a proper closing in a business letter. Use a comma (,) after it. Sign the Letter: Always sign the letter in ink. If sending a printed copy, always affix the scanned signature. Make Note of Enclosure: One must properly enclose a list of attached documents with the letter. One can use the abbreviation of the enclosure, i.e., Encl. or Enc.