Why can't the phone case send text messages?

If you change your phone case to someone else's phone, you can see it by SMS. When the SIM card is replaced by a mobile phone, the information disappears, indicating that the information is stored in the memory of the mobile phone or SD card. The solution is to download QQ communication assistant on the original mobile phone, log in with QQ number, and click SMS backup. Download QQ communication assistant on the new mobile phone, log in with QQ, and click SMS to recover from the network. In this way, the text message was restored to the new mobile phone. So, your mobile phone case is changed on someone else's mobile phone, and the text message can be seen.