Report on sending short messages on mobile phones

"Information validity period" refers to the longest valid time for your mobile phone to receive short messages.

"Not sent to * *" is the sending report of your mobile phone. Send a short message to the other party, and the other party will receive a "sent (number)" report when receiving the short message. If the other party does not receive it, you will receive a report of "Not Sent to * *". As for receiving such a report in two days, it was because the "information validity period" set by the other party was two days, so he didn't receive the news for two days or because of arrears. You will receive the message "Not sent to * *".

"Overflow" means you can't get it. It's empty