An image forming apparatus includes an event notification data preparing unit, an event notification data transmitting unit, an information-processor count calculating unit, and an information-processor count determining unit. The information-processor count calculating unit calculates a count of the at least one information processor to which the event notification data is transmitted. The information-processor count determining unit determines whether the information-processor count is equal to or less than an upper limit value for the event notification count. The event notification data transmitting unit directly transmits the event notification data to the at least one information processor if the information-processor count is equal to or less than the upper limit value for the event notification count, and via the server transmits the event notification data to the at least one information processor if the information-processor count is more than the upper limit value for the event notification count.