Why can't Lenovo a6 Unicom receive SMS?

There are the following reasons for not receiving SMS or verification code:

1. Check whether the mailbox is full first, and if so, please delete some information;

2. If you still can't receive it after deleting it, you can change the machine or card to see if it is a hardware factor;

3. after eliminating the above reasons, we 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 problems do not exist, please contact Unicom's human customer service for handling.