After receiving an SMS message, the recipient mobile phone will send back a message delivery report to the SMS center to inform whether there are any errors or failures (example causes: unsupported SMS message format, not enough storage space, etc). This process is transparent to the mobile user. If there is no error or failure, the recipient mobile phone sends back a positive delivery report to the SMS center. Otherwise it sends back a negative delivery report to the SMS center.
If the sender requested a status report earlier, the SMS center sends a status report to the sender when it receives the message delivery report from the recipient.
Once your phone receives the SMS, you can decide whether to block it. In case you wanna block it, the application has to simply send a Storage full / Message format not supported Error to the message station instead of normal status.
There's always a way guys