Why do text messages sent to me by others always take a long time to receive?

I went to check it out.

. . .

SMS is not a real-time service, and the sending success rate can't reach 100%. The missed receipt of short messages may be caused by many reasons. For example, when the SMS center (the service provider's equipment) sends you a message, you happen to be in a bad place, so the message is not sent successfully for the first time, and then it will enter the retransmission mechanism of the SMS center. In other words, the short message center will send you another short message every once in a while. If it fails all the time, this short message will not be sent again after its validity. In fact, this is just an example. Because a short message you receive may be sent through multiple devices, including short message center and short message gateway, it is normal to miss the short message occasionally.

2. It is normal to occasionally fail to receive the sending report after sending the text message. This will also happen if your mobile phone terminal and wireless terminal do not cooperate well. Even if you receive a successfully sent status report, the other party may not receive the short message. The status report you received only indicates that your message has been submitted, but the final situation of sending it to the other party is still uncertain.