Is there any hint that the other party refuses to send SMS?

If the other party is in the power-off state, there is a prompt of sending failure, and if the other party blacklists the sender's mobile phone number through software.

Generally divided into two situations.

1, one is to reject the message directly, and the other is to put the message into the blacklist software. If it is rejected directly, it will prompt that sending failed.

2. If there is no prompt in the SMS blacklist software, the sender can check the SMS list, and if the sending number is displayed, the sending is successful.