1. A method for organizing a plurality of e-mail messages for electronic discovery investigators, the method comprising: receiving, at one or more computer systems, a plurality of processed e-mail messages, the plurality of processed e-mail messages including a plurality of transactional e-mail messages and a plurality of derived e-mail messages derived from the plurality of e-mail messages in response to extracting information from message attribute data of one or more of the plurality of transactional e-mail messages to create the plurality of derived e-mail messages; determining, with one or more processors associated with the one or more computer systems, an e-mail rank for each e-mail message in the plurality of processed e-mail messages as a weighted average of a sender value determined for a sender identifier related to the e-mail message and a recipient value determined for each of one or more recipient identifiers related to the e-mail message, the sender value further quantifying text contributed to the e-mail message by the sender of the e-mail message; determining, with the one or more processors associated with the one or more computer systems, a plurality of e-mail threads associated with the plurality of processed e-mail messages, each of the plurality of e-mail threads including one or more of the plurality of processed e-mail messages; determining, with the one or more processors associated with the one or more computer systems, a thread rank for each e-mail thread in the plurality of e-mail threads based on a weighted average of one or more e-mail ranks associated with the one or more of the plurality of processed e-mail messages associated with the e-mail thread; organizing, with the one or more processors associated with the one or more computer systems, the plurality of processed e-mail messages based on the thread rank of each e-mail thread in the plurality of e-mail threads; generating, with the one or more processors associated with the one or more computer systems, information configured to display to electronic discovery investigators on a graphical user interface the organized plurality of processed e-mail messages; and wherein determining the plurality of e-mail threads further comprises: determining, with the one or more processors associated with the one or more computer systems, whether an e-mail message to be placed in an e-mail thread is a duplicate of an e-mail message in the e-mail thread; and associating, with the one or more processors associated with the one or more computer systems, the e-mail message to be placed in the e-mail thread with the e-mail thread when the e-mail message to be placed in the e-mail thread is determined not to be a duplicate of any e-mail message in the e-mail thread.