Systems, methods and computer-readable storage media for modifying presence and electronic messages are described; the system includes a sending terminal, at least one modification parameters database, which contains a plurality of modification parameters, at least one message modification agent and a recipient moiety, including a message user agent, in which the modification parameters in the database are updated dynamically; the method includes sending a message, obtaining at least one modification parameter, from a database which contains a plurality of modification parameters, applying to the message at least one modification parameter by a message modification agent and delivering a modified message to the recipient.