Customize Unicom SMS receipt service. Can I know if the other party blocked my SMS?

Dear, the "short message receipt" service refers to the service that the system sends a receipt to the user to prompt the sending status of the short message after the user sends the short message, but the short message receiver is limited to China Unicom users (that is, 2G and 3G users, excluding PHS users).

When the short message sent by the user is successfully sent to the receiver, the sender will receive a receipt notification short message to inform the receiver that the short message sent by the user at a certain time has been successfully received; If the short message fails to be sent finally, the sender will also receive a receipt notification short message to inform the receiver that the short message has not been received, but it is impossible to determine the cause of the failure, such as the other party's mobile phone has no signal and has not been turned on for a long time.