Why can't Unicom receive and send short messages?

The handling methods for Unicom mobile phone users who can't send short messages are as follows:

1. Replace the mobile phone to see if they can send and receive short messages.

2. Replace the mobile phone card, put it into other mobile phone cards to send and send information to this mobile phone card, and test whether the mobile phone card is faulty;

if all the above attempts are made, it is still impossible to send and receive. It is not excluded that the SMS function of the mobile phone card is abnormal. You can contact customer service to check the SMS function of the mobile phone card.