A business letter is an official dealing with the subjects such as enquiry, order, request, complaint, and apology.
Salutation used in business letter
It names the person or people addressed.
It should be placed two spaces below the inside address.
If the recipient of the letter is a man, Dear sir should be the salutation. Dear Madam, is the salutation for a woman. But if the letter is addressed to a business firm, the greeting is – Dear Sirs.