Knowledge-based mail systems (KMS) have been developed to sur-mount the communication barriers of traditional electronic mail systems. However, little attempt has been made to ground these systems in organizational communication (OC) theory. We have reviewed 14 existing KMSs; they provide a framework for classifying these systems in terms of the mechanistic, psychological, systems interaction, and interpretive-symbolic perspectives in OC theory. This framework provides a basis for resolving e-mail usage problems.