Why did Unicom send a short message to show that sending failed? Unicom's customer service has been unable to get through.

There are many reasons why SMS can't be sent normally, depending on whether the user belongs to a new card and has been unable to send SMS normally, or whether it can be sent suddenly before; If the new card cannot be sent normally, the SMS function may not be enabled, or the SMS center number may not be set; If it used to be possible, it can't be sent suddenly now, or it may be because the terminal and SMS system are busy, or the short message sending function is temporarily limited due to the large number of group sending.

Tips: If you still can't send SMS normally after all the above reasons are investigated, you can suggest going to the local operator's business hall or calling the operator's customer service hotline for consultation and reflection.