This letter, called the personal business letter, has the return address written above the date line. It is important that you include the return address as part of the heading of this letter, because this information is not shown in a letterhead. This letter form would be proper for in any business matters than an individual might have.
In this example the modified block style is followed. There is a colon after the salutation and a comma after the complimentary closing. You might choose to use block style with or without marks punctuation. Any such choices would be acceptable.
Many people prefer indented paragraphs and the inclusion of punctuation marks after salutation and closing. Therefore, this letter style is used a great deal.