Using the online survey method, this study investigates how consumers regard unsolicited commercial e-mail (spam) and their possible responses. Specifically, the study closely examines the relationships among five key indicators: (a) perceived intrusiveness, (b) perceived irritation, (c) attitudes toward the advertising medium, (d) ad skepticism, and (e) ad avoidance. Also examined is the process of attitude formation concerning unsolicited commercial e-mail. The results indicate that while perceived intrusiveness increases the likelihood of avoiding unsolicited commercial e-mail, perceived irritation tends to raise the degree of ad skepticism.