My Xiaomi 4S mobile phone can receive messages, but can't send short messages. Other phone calls and online chats are normal.

1: First, confirm whether all the short messages sent to all numbers can't be received. If you can't receive some short messages, please pay attention to whether the number you can't receive is the same operator. For example, only mobile users can't receive it, and other operators are normal, so Unicom numbers are set to intercept short messages sent by mobile users. This situation is generally due to a large number of advertisements or spam messages sent to mobile users by this number in the early stage, which leads to limited mobility. If you need to cancel, you can contact 100 10 customer service for help. 2. If all the short messages are not received, you can change to other Unicom cards for local testing (the cards of other operators are changed by mistake because the numbers of SMS centers of operators are inconsistent). If the number is changed, it can't be sent. Please call 100 10 customer service to check the number of the SMS center and make changes to the mobile phone settings. 3. If this machine can be sent by changing other Unicom numbers, it does not rule out that there are too many short messages sent in the early stage, or sensitive keywords are automatically closed by Unicom system. Please call 100 10 to verify whether it can be restored.