Will the mobile phone be dropped, so that the text message cannot be sent out?

1 Let's see if it's a message sent by China Unicom. If so, I will often send you a receipt when Unicom has not received the news, or a similar phenomenon will occur when the Unicom card issued is no longer available ~ ~ I have a deep understanding of this ~

Is it always in the same area or place when this happens? Maybe the signal in that place was bad at that time.

If none of them are, it may be a sign that the internal components that send signals are loose or broken, that is, you need to repair them.