How to query the short message content of mobile phone card? Not very grateful!

If both messages are deleted, it will be difficult to find the content of the messages that have been sent and received. The principle of sending SMS is that the sender uploads the SMS content to the mobile and Unicom SMS gateways first, and then downloads it to the receiver's mobile phone after instant processing. Therefore, in theory, China Mobile and China Unicom can query the content of short messages, and both claim that they cannot query the content for the purpose of "protecting users' privacy".