System and method for evaluating a structured message store for message redundancy

A client system, for storing electronic messages for redundancy processing, comprising:

• a plurality of electronic messages that each comprise a message header plus a message body, at least part of which is used to determine a hash code for each electronic message;
• and
• an interface providing access to the electronic messages, wherein the electronic messages with matching hash codes are assigned into groups and one such electronic message within each group is identified as unique, wherein at least one such electronic message further comprises one or more attachments, at least part of which is used to determine a further hash code and the electronic messages within each group with matching further hash codes are identified as exact duplicates.

An analysis system processing electronic messages for redundancy, comprising:

• a plurality of electronic messages that each comprise a message header plus a message body wherein at least one such electronic message further comprises one or more attachments;
• and
• a processor configured to determine hash codes from at least a part of each electronic message header plus message body and to assign the electronic messages with matching hash codes into groups, wherein one such electronic message within each group is identified as unique and to determine further hash codes from each attachment, the electronic messages within each group with matching further hash codes are identified as exact duplicates.