Mobile phones sometimes receive text messages that open automatically, and there is no number yet. What happened?

My answer is the same as that upstairs. Generally speaking, this is Nokia's "instant messaging" device. I know that only Nokia can send such a message. I once sent such a message to my friend. They all thought their mobile phones were broken. You still want to ask your friend who uses Nokia's mobile phone. Such information can be replied. Don't quit after receiving it, just reply directly.