We examined the effects of mood and the content (a priori valence and involvement) and formal (presentation modality: text vs. video) characteristics of messages presented on a small screen on emotional responses and involvement among 47 young adults. Mood was induced by autobiographical memories varying in affective valence and arousal. Facial electromyography (EMG) and cardiac interbeat intervals were used as physiological indexes of valence and arousal. Both mood and the emotional tone of a message exerted an independent influence on the emotional response to the message. A strong valence-related mood-congruency effect emerged in predicting involvement. The text modality elicited higher involvement, arousal ratings, and orbicularis oculi EMG activity compared to the video modality when in a depressed mood, whereas the reverse was true when in a joyful, relaxed, or fearful mood. The results point to the possibility of mood-adapted media services.