An e-mail system is disclosed that overcomes many deficiencies of, but is backward compatible with, existing e-mail systems. An exemplary method for communicating e-mail messages comprises receiving, at a server system, an original e-mail message associated with a unique message ID that is assigned by the server system. The method further comprises storing a distribution list associated with the unique message ID and a thread participation status indicator for each of the one or more recipients, and, in response to an opt-out request received from one of the recipients, updating the distribution list to thereby produce a modified distribution list that does not include the requesting recipient. The method further comprises receiving a reply e-mail message in the same thread, and sending the reply e-mail message based on the modified distribution list such that the reply e-mail message is not sent to the requesting recipient.