I want to ask, why can't Nanjing Unicom send text messages?

1. There is a problem with the number setting of the SMS center. It is recommended to check whether the settings are correct. 2. The system is busy during the peak period of holiday SMS sending, so it is suggested to try again later or avoid the peak period. 3. The sending format is incorrect. If you send a short message to PHS users, you need to add the area code before the number; 4. The SMS inbox and sending box are full; 5. Query whether the SMS function is turned on. If the above situation has not been solved, it is recommended to contact the local manual customer service for handling.