How to clear the red exclamation mark in Apple SMS?

Clear the red exclamation mark of Apple SMS as follows:

Operating environment: iPhone 13pro, iOS 16, set version 4.45.

1. Enter the settings that come with your Apple phone, find the notification, and press Enter.

2. Slide the interface in the notification to find the information and click Enter.

3. After entering the information, find the marking option, click the button behind Close to remove the red corner mark.

Causes of failure to send short messages

1, due to network instability or network loss. Just confirm whether the network connection is normal, and then click resend.

2. The sent SMS contains illegal content and has been blocked. Please change the sentence or phrase and send again.

The other party has blacklisted you, and the information you sent cannot be received by the other party. You need the other party to lift the blacklist restrictions before sending it out.

4, mobile phone arrears, when your mobile phone arrears, mobile phone text messages can not be sent out, you can resend after payment.

5. Memory space may be insufficient. When the memory of the mobile phone is insufficient, it will also happen that the short message cannot be sent out.

6.iMessage was not successfully opened or activated. Need to restart iMessage and send SMS.