Why didn't others give them a short message screen effect after receiving it?

Such information is sent by a mobile phone with the function of "sending instant messages". After receiving it, the other party will automatically open it and display it on the mobile phone screen. When you finish reading and exit, this message will disappear automatically. After exiting, there is no way to find the original information content and sending source number. My Nokia phone has this function/it should be said that this kind of short message is also called flash message. At present, the whole country supports sending this kind of short messages, but it is only necessary to add a code before the mobile phone number sent. Now different provinces add different codes, such as Shanghai plus 0 18 and Anhui plus 0 106585 1 1, which can be seen on the websites of various mobile companies. If this short message is particularly important, the mobile company can certainly find out who sent it, provided that you have certain authorization for the mobile company to check it, but I'm afraid the content can't.