The invention is an instant-messaging system that minimizes undesirable alerts on an exposed output device. The instant-messaging system is configurable so that a user can select an alert mode that alters the instant-messaging system's response to receiving message data from a caller while a user is operating an exposed output device. Specifically, a user can select a “do-not-disturb” mode, a “designee” mode, a “caller-id” mode, or a “priority” mode. If the user selects the do-not-disturb mode, the system blocks the message and informs the caller that the user does not wish to be disturbed. If the user selects the caller-id mode, the system displays the caller's identification and then prompts the user to accept the message. If the user selects the priority mode, the system displays the caller's identification only if the caller is in the user's “priority list.”