Why does Apple's SMS always have a red exclamation point? Why does Apple's mobile phone have a red exclamation mark?

1. There is a red exclamation mark above the SMS function of Apple's mobile phone. Click to enter information.

2. In the information interface, you can see a prompt message below the message that failed to be sent.

3. After clicking enter, you can find that a short message was not sent.

4. At this time, you can click the red exclamation mark of the message, and a window will pop up at the bottom of the page. Click Retry to send again.

5. If the message cannot be sent and the red exclamation mark is still displayed, please turn on the phone settings.

6. In the setting interface, click "Enter Information". On the information page, just open iMessage.

7. After opening iMessage, wait for two minutes, then open the message and send it again. At this time, the short message can be successfully sent.