Why do the messages sent from my mobile phone always have question marks?

Generally, this situation occurs because the other party’s mobile phone does not support receiving MMS messages. However, since you are sending a text message, as long as it is normal when you send it, it should be a problem with the other party's mobile phone. Also, the text message content is too much and exceeds the SMS capacity of the other party's mobile phone (for example, if you send a 60-character text message, the other party's mobile phone will (a text message is 50 characters), such problems are prone to occur. Try sending a few words and try!