Date: Use month, day, year format, e.g., March 3, 2013 or 3 March 2013
Sender's Address: It is a good idea to include sender's email and url, if available. Don't include this information if it's already incorporated into the letterhead design. This will allow customers to find your small business more quickly.
Inside Address: Use full name. Mr./Ms. is optional.
Salutation: Be sure to use a colon at the end of the name, not a comma as in personal letters
Body Text: State why you are writing. Establish any connection/mutual relationship up front. Outline the solution, providing proof in the way of examples and expert opinions. Group related information into paragraphs.
Closing "Call to Action": State what the reader needs to do and what you will do to follow up.
Signature Block: Sign your letter in blue or black ink.
Enclosures: Use if you have an enclosure.
Carbon Copy: Use if you are sending a copy to additional person(s).