1. Verify that there is no sensitive word in the message content, or the message with the same repeated content is sent to the same number, so the message is screened by the operator. For details, contact the local operator.
2. If only the short messages in an area cannot be received, possibly the connection between the area and the local SMSC is faulty. In this case, consult the customer service of the operator about when the fault can be recovered.
3. If the verification code message cannot be received, it may be caused by network delay or server communication delay. Wait until the second reading is completed, and try again. You can also contact the corresponding platform to request the verification code.
4. Short messages cannot be sent to mobile phones of some brands. It is possible that these mobile phones block short messages, or the processing of these mobile phones is faulty. You can put the SIM card on another mobile phone for comparison.
5. If a single SMS message cannot be sent, possibly the status of the SMS database is incorrect. You can delete the SMS message and edit it again before sending it.