I can't send a text message to 12306. What happened?

The reasons why SMS can't be sent out are the limitation of SMS sending, network problems, SMS service restrictions and so on.

1, SMS sending limit: Some mobile phone operators or packages may limit the number or time of SMS sending. Exceeding the limit may lead to the failure of SMS sending, so SMS sent to 12306 cannot be sent.

2. Network problem: If the mobile phone network signal is unstable or the network cannot be connected, it will lead to the inability to send short messages to 12306.

3. SMS service restrictions: Some mobile phones or operators may have special restrictions or configurations on SMS service, which will affect the sending of SMS.