1. A method of constructing a listing of e-mail messages, the method comprising: retrieving, by at least one server, information in respect of a plurality of e-mail messages from at least one database in electronic communication with the at least one server, each e-mail message including a header having a plurality of header fields and a body having content; sending, by the at least one server to a client device via a communications network, instruction to display in one of an e-mail message listing pane or an e-mail message listing window in a graphical user interface of the client device, a listing of e-mails, the listing including in respect of at least some of the e-mail messages listing information including at least some of the header fields; for at least some of the e-mail messages, one of determining a classification of the e-mail messages by the at least one server and retrieving from the database a classification of the e-mail messages by the at least one server, the classification including a sender type and at least one message type, the sender type having been determined from a plurality of potential sender types, via a first analysis of the header and the body, the first analysis including application of at least one first complex rule, each applied first complex rule including a first plurality of elementary rules specific to that applied first complex rule, at least some of the first plurality of elementary rules specific to that applied first complex rule including a regular expression analysis, the at least one message type having been determined from a plurality of potential message types, via a second analysis of the header and the body, the second analysis being distinct from the first analysis, the second analysis including application of at least one second complex rule, each applied second complex rule including a second plurality of elementary rules specific to that applied second complex rule, at least some of the second plurality of elementary rules specific to that applied second complex rule including a regular expression analysis, the second plurality of elementary rules being distinct from the first plurality of elementary rules, the determination of the at least one message type being independent of the determination of the sender type; receiving, by the at least one server from the client device via the communications network, a request to order the listing of e-mails by e-message classification; ordering, by the at least one server, based on the classification of the e-mail messages, the listing of e-mails by e-mail classification; and sending, by the at least one server to a client device via a communications network, instruction to display in the one of an e-mail message listing pane or an e-mail message listing window in a graphical user interface of the client device, the ordered listing of e-mails.