Issues related to changing modes of business communication, particularly those that are computer-mediated, are discussed as they relate to the teaching of business English. Information about current practices in computer-mediated communication (CMC) drawn from the business press and research journals is summarized, focusing on that which can help a business English teacher teach realistic, up-to-date business electronic mail (e-mail) usage. Discourse features of both synchronous and asynchronous CMC are described, including register, tendency toward simplification, and the phenomenon of "flaming." Technical features of e-mail are also noted, including message format and reply capabilities. A discussion of the business norms reflected in e-mail looks at headers, informal language, abbreviation, volume of information conveyed, reply conventions, and specific notations to express emotions. Some issues in teaching e-mail communication are also noted, including the role of error correction and use of authentic e-mail as instructional material. Contains 22 references. (MSE)