H04L51/00
User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
H04L51/00
User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
H04L51/224
providing notification on incoming messages, e.g. pushed notifications of received messages
H04L51/224
providing notification on incoming messages, e.g. pushed notifications of received messages