1, SMS center number is set incorrectly;
2. There is no signal or the battery of the mobile phone is insufficient;
3. 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 of sending;
4. The sending format is incorrect. If you send a short message to PHS users, you need to add the area code before the number;
5. The mobile phone shields the short message sending function;
6. Blacklisted by SMS;
7. Insufficient quantity balance;
8.SMS inbox and outbox are full.
If the above situation has not been solved, it is recommended to contact the local manual customer service for handling.