Abstract: A method for negotiating an electronic mail transaction. An electronic mail message's mail type specifier is identified. A data store stores data specific to the intended recipient. The data store is referenced and the electronic mail message is processed as a function of the mail type specifier and data retrieved from the data store. The mail may be processed at the recipient's mail client device and the information maintained confidential. The processing may be based upon reference to a rule applicable to that particular message. The rule includes a conditional instruction conditioned upon a result of a logic or other function of recipient profile data. Alternatively, the processing may provide for modification of the content of the message as a function of such recipient profile data. Recipient preferences from multiple recipients may be aggregated and propagated to senders and/or intermediaries to allow for pre-transmission processing of electronic mail messages.