Systems and method for delivering messages are provided in which a plurality of messages to be electronically sent are stored in a storage unit. Each of the respective messages includes associated metadata describing information about the respective message. The storage unit includes local storage which stores a first amount of information describing imminent messages, which are more likely to be sent, and stored a second amount of information, less than the first amount of information, describing non-imminent messages which are less likely to be sent. The storage unit also includes remote storage, which stores additional information about the messages. A processor operates to determine information about each message, and manages an amount of information about the messages which are stored locally.