The purpose of this study was to investigate guidelines for instructional use of e-mail and the method in the present investigation was followed by an analysis of research literatures. This study suggests the following conclusions. First, instructors should use e-mail effectively to improve communication between an instructor and a learner or learners. Communication was essential to support a good instruction. Second, to use effectively e-mail in teaching and learning process, guidelines should followed by considering e-mail characteristics. These guidelines were as follows: (1) Spelling and grammar should be followed correctly. (2) Messages should be followed shortly and concisely. (3) Summaries should be stated in your first sentence. (4) Messages should be responded rapidly. (5) Messages should be responded kindly. (6) Sarcasm and humor should be used carefully.