What are the three main reasons why text messages can't be sent out?

1, mobile phone is in arrears: if your mobile phone is in arrears, or even turned off, you can't send text messages. So when you can't send a text message, the first reaction is to check whether you owe money.

2. The other party has a firewall: If the number you want to send has a firewall, your message will be rejected. In this case, it will show that the delivery was successful and the receipt failed. Although the other party can't receive it, it will still charge you the SMS fee.

3. Signal problem: Although there will be network coverage in most places now, network instability is inevitable. When your short message can't be sent out, it is likely that the network is not good or there is no coverage. Moving a place or restarting your mobile phone may solve the problem.