Sometimes the received text messages need to be read. What happened? If you hadn't opened it, you wouldn't have known where the mail was stored.

This is called "service information" with URL. If you open and check the connection, you will have to pay GPRS traffic charges. If you refuse, it may be automatically deleted by your mobile phone. There are some differences in the processing methods of mobile phones from different manufacturers. Some of them put general information in their inboxes, some temporarily display it, and some have special directories to store it. For details, please check the hunger instructions or call customer service.