The letter is the formal mechanism for communication in the business community. Even contemporary advances in electronic mail have not yet displaced the legitimacy invested in this form of correspondence. However, its very functionality has detached it from the fabric of its social history. This history locates its roots in early letter writing manuals and reveals an epistolary transition from fawning flattery to professional neutrality. The paper examines the history of this particular transformation and suggests its lasting influence in constructing notions of credibility around the contemporary business letter.