It's been sent six or seven times. I have already sent it. He said he didn't receive my message.

According to the information you provided, the reasons for not receiving the SMS are as follows:

1. Please check whether the mailbox is full first. If it is full, please delete some information.

2. If it is still not received after deletion, you can change the machine or card to see if it is a hardware factor;

3. After eliminating the above reasons, you can try to test whether it can be received in other places to see if it is the reason for the weak local signal.

If the above problem does not exist, please contact the local Unicom manual customer service to handle this problem.