Why can't others receive the short message I sent by Fetion?

You should be talking about the network problem, because since you said that you sent someone a flying letter and he couldn't receive it, that means you added them as friends, because you can't send them a flying letter without adding them as friends. In addition, if the other party doesn't apply for a flight signal, you can't add them as friends. Once added, the system will say that the other party has not opened Fetion service, so be sure before adding friends. Fetion takes up a lot of traffic. When your mobile phone network signal is poor, such as during rush hours or when a large number of people use your mobile phone to surf the Internet, it often happens that you send a message, but the other party didn't receive it, or it took a long time to receive it, so it is recommended not to send it when your mobile phone network signal is poor, so the other party may not receive it ... I hope it will help you.