This article explores the potential of E-mail as a medium of patient-physician communication. It introduces control tactics that physicians can consider to increase the efficiency of the medium. These include pre-qualifying the patients receiving the physician's E-mail address, establishing a code for high-risk patients, responding to E-mail only during "down time," using response templates, off-loading standard questions, establishing a quota, and establishing user expectations. The author suggests that if physicians develop a discipline around handling E-mail, they can increase their effectiveness by developing closer ties with patients without sacrificing extra time.