A method and related apparatus for delivering a message from a calling party at a calling station to a called party at a called station, the method including: in response to an unsuccessful attempt to communicate from the calling station to the called station, storing a message from the calling station,...http://www.google.fr/patents/US6535585?utm_source=gb-gplus-shareBrevet US6535585 - System and method for notification upon successful message delivery
System and method for notification upon successful message delivery
