What is the message that the other party can't receive?

Several reasons: 1, your mobile phone or your friend's mobile phone has no phone bill; 2. When sending a message, your mobile phone or your friend's mobile phone is not in the service area, that is, the signal is blocked and you cannot receive the message; 3. elevators, basements and other places with weak signals can't receive information; 4. You can't receive the information because the network operator you use or the network operator your friend uses is delayed and the information sent out fails.