Samsung GTi5508 cannot send text messages, what should I do?

This situation is usually caused by the wrong SMS center number

Please find the SMS center number in the SMS settings and set it to your local mobile SMS center number.

Our local China Mobile Short Message Service Center number:

+8613800311500

You just need to set it to your local one (set it to the basic one here) Yes), please call 10086 to find out what the local SMS center number is. Then the setup should be no problem.