Apple 12 SMS pdf can't be sent out.

Solution to the problem that SMS cannot be sent.

1. Open the iPhone settings, check whether the flight mode is turned off because of the flight, and check whether the mobile phone is in arrears. Please pay the phone bill in time and try to turn off the phone and restart it.

2. You can also pull out the mobile phone card and plug it in again, or try to send text messages with other mobile phones. If you can't send text messages, it may be because there is something wrong with the SIM card, such as

3. The mobile phone is in the operator's signal blind area, or the surrounding mobile phone signal is blocked, resulting in unsuccessful transmission.