The number displayed after sending the SMS is invalid.

1. Enter the SMS Outbox, click this undeliverable message and move it into the draft box;

2. Enter "Menu-Tools-Scene Mode" and select "Offline". At this time, the phone is offline;

3. Go back to the short message draft box and send the short message offline, and a prompt "Saving in Outbox" will appear;

4. Turn it off and on again, and "Continue to use the phone in offline mode?" To ask a question, select "No". After the phone is turned on, the short message can be sent!