Intercept each other's text messages. Does the other party know?

Intercept each other's text messages. The other party doesn't know. According to the public information related to the query, it shows that SMS interception is set, and the other party does not know after interception, thus blocking the other party's notification. When the other party sends a message, his message is set to have a delivery report, so after interception, his mobile phone will receive a short message indicating that the message was not sent successfully.