When is it best to write a letter instead of an e-mail

"This Element is an excerpt from The truth about the new rules of business writing (ISBN: 9780137153152) by Natalie Canavor and Claire Meirowitz. Even in the digital age, businesspeople use letters for building client relations, proposals, references, invitations, and other formal occasions of the business world. In each case, the step-by-step process will focus your thinking so you come up with the right presentation"--Resource description page.