This study examined the use of ARCS-based, motivational mass e-mail messages designed to improve the motivation and retention of students enrolled in an online, entry-level, undergraduate computer applications course. Data from the Course Interest Survey, based on Keller's ARCS model, were gathered and analyzed for two online groups (one treatment and one control) and compared with a face-to-face class for differences in attention, relevance, confidence, satisfaction, and overall motivation. Based on the analysis, this article argues that simple, cost-effective, and easy-to-design mass e-mail messages show potential for addressing some of the motivational needs and retention concerns of online students. (Contains 6 tables.)