Why can’t my iPhone send text messages and an exclamation mark appears?

1. The mobile phone is in arrears and shut down.

2. Are your Iphone MMS settings correct? The three operators have different methods of setting MMS. To be correct, it should be whether those English inputs match your carrier card.

3. Call 10010 to report a mobile phone service failure. Ask the service staff to tell you the SMS center number.

2. Enter: ##5005*7672# (call) to clear the original wrong SMS center number of this machine.

3. Input: *5005*7672* 86 (130XXXXXXXX correct SMS center number)# (press and hold the 0 key to exit)

4. Input: *#5005*7672# Check whether the number is entered correctly.

5. Mobile phone settings page-General-Network, turn off cellular data and 3G.

6. Mobile phone settings page-message-iMessage, open.

7. Restart.

8. Turn on cellular data and 3G.

The solution to the problem that iPhone 4 cannot send text messages is as follows:

1. Is the signal of the mobile phone normal?

2. Check whether the SIM card status is normal.

3. Check whether the send button is bright and clickable.

4. If you cannot click send after entering text, the "Send" button will still be gray and cannot be clicked. Please go to Settings > SMS > turn off "Show subject bar".

5. If it is a group text message and the numbers are entered manually, please make sure to use line breaks instead of spaces to separate each number.

6. After the above problems are eliminated, you can first check whether the SMS center number of your mobile phone is correct. If it is incorrect, you can delete it and then reset it. After setting it, you can also check again whether the SMS center number is correct.