IPhone6s failed to send messages. Why can't I accept short messages?

1. For users who have turned on iMessage in the settings-information of iPhone, as long as the other party is also an Apple phone and has turned on iMessage information, they will use the network to send information.

2. As shown in the figure below, the word iMessage is displayed in the current SMS input box, indicating that the information is currently sent by the network.

3. When sending iMessage message, the system will use wireless network or mobile network to send it, so if the current iPhone is not connected to the wireless network or the mobile network signal is not good, the information transmission will fail. As shown in the following figure

4. As shown in the figure below, when the message has not been delivered, if the current network signal is not good, you can click the red message icon.