Why does a red exclamation mark appear in text messages on mobile phones?

A red exclamation mark indicates that the message was not sent successfully.

This situation may be caused by the following reasons:

1. It is usually caused by unstable network or no network. Just confirm that the network connection is normal and click Resend.

2. If there is any illegal content in the sent message, it will be blocked. Just change the wording or phrase and resend it.

3. The other party has set you up on the blacklist. The other party cannot receive the messages you send, and the other party needs to lift the blacklist restriction.

Solution (taking vivo X9 mobile phone as an example) check whether the SMS center number is correct:

1. Enter settings from the standby desktop

2. Information

3. SMS center number

4. Check whether the SMS center number is correct