a system for managing message volume and timing , which permits messages from multiple sources to be spaced apart over time , with the pacing controlled in part by the type or priority of the message . the system permits the volume of messages to be reduced by aggregating messages according to a set of rules and by discarding or delaying messages that are sufficiently similar and sent too close together . in addition , the system allows message sources to be notified when a recipient has not received a message within a designated time period . the system can be implemented as a centralized pacing system or through use of a data storage system accessible by the message sources .