A system and method for evaluating a structured message store for message redundancy is described. A header and a message body are extracted from each of a plurality of messages maintained in a structured message store. A substantially unique hash code is calculated over at least part of the header and over the message body of each message. The messages are grouped by the hash codes. One such message is identified as a unique message within each group. In a further embodiment, the messages are grouped by conversation thread. The message body for each message within each conversation thread group is compared. At least one such message within each conversation thread group is identified as a unique message.