The network message of Xiaomi's mobile phone, but the other party does not open the network. Why can I send network messages? ...

It is impossible to send a free network message without surfing the Internet, because the mobile phone will not be displayed as a free network message, unless it is possible that when you send a message, the other party is connected to the network, and when the other party has not received the message, the network is disconnected or considered closed. In this case, the free network message will become a regular message and be received by the other party.