Fetion can't send short messages

First of all, you are a mobile phone client, and the other party is just an online SMS user. You send a message to the other party first, and the other party's mobile phone will receive your short message, but when the other party returns, it will send you a short message instead of flying a letter. Because he is not a mobile phone client, you received the message from the other party through Fetion and SMS, and you may not have accepted the other party as a friend.