A business letter is a formal letter, which acts a medium of correspondence between two business entities. It can be a letter written by one organization to another, or a letter written by an organization to its clients or customers. Business letters are further divided into several types, ranging from a letter of inquiry to a letter of agreement. Irrespective of which type it is, the business letter format has some common elements, like the address (of the sender as well as recipient), subject, date, salutation and valediction. Among these elements, one of the most important element is business letter salutation. Although it's of utmost importance and widely used, when we take to letter writing, many of us still tend to get confused about what to use and what not to use. Read more on proper business letter format.