A method of communicating messages between a sender and a recipient using a communications protocol over a data network, which includes: (a) receiving communication preferences specified by the recipient that includes constraints required to be met for delivery of a message, (ii) publishing the profile with visible preferences from the communication preferences of the recipient when the sender selects the recipient to send the message, (iii) processing a request received from the sender to send the message to the recipient, (iv) generating a customized message form based on the communication preferences of the recipient to enable the sender to compose the message, (v) providing an indication to the sender if any of the constraints are not met, and (vi) delivering the message to the recipient when the constraints specified by the recipient and any constraints applied by a messaging system are met by the message.