The validity period of SMS

If your mobile phone is turned off, it will not show that the message was sent successfully, so it will not appear on the mobile platform. The longest time limit for the other party not to receive the message is 72 hours, which means that if you send a message, the other party can keep it on the mobile platform for 72 hours. After the other party turns on the phone, you can't see your message. Another possibility is that your message will be in the message you sent before. He will deliver it automatically after you pay the fee. It also has something to do with your mobile phone after it is turned on.