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.