Unicom iphone4 can't send short messages, can receive messages from others, can answer the phone, has no arrears, and has set up a short message center. What about swelling?

If your iPhone can't send text messages, please do the following troubleshooting: 1. Make sure the signal is normal and turn off the flight mode. Since you can receive short messages from others, this can be ruled out. 2. Check whether the sim card status is normal. I suggest you put your mobile phone card in other mobile phones to see if the same problem will occur. If so, there may be something wrong with the SIM card. Suggest going to the business hall to check. 3. Check whether the send key is bright and clickable. 4. If you can't click Send after entering the text, the "Send" key is still gray. Please put it in.

> SMS

Turn off the display of the subject bar. 5. If you send text messages to multiple people and manually enter numbers, please make sure to use line breaks instead of spaces to separate each number.

6. Whether the Outbox is full, so it cannot be sent. Your SMS center number is correct, and you can't send it even if the above situation is ruled out. It is recommended to go directly to the local Unicom business hall for inspection.