SMS does not show delivery.

1. When the message is hacked, it will not show that it has been delivered. Short message is text or digital information sent or received directly by users through mobile phones or other telecommunication terminals. The number of characters that users can send and receive SMS at a time is 160 English or numeric characters or 70 Chinese characters.

2. Network problems and setup problems. Network problem: the network transmission failed, and the mobile phone has not set a receipt report, so it is impossible to see whether the short message was sent successfully. Setup problem: the mobile phone does not have a reminder of successful SMS sending, which can be set in the setup notification.

3. The message was sent out, but it didn't show that it had been delivered, which can't completely explain that the other party pulled you into the blacklist. It is possible that network fluctuation and other reasons lead to the failure of information sending and receiving. At the same time, the other party's equipment may be out of order, not turned on or the software is abnormal, resulting in the information not being delivered in time.