Mobile phones (Unicom, htc) send short messages to others, and the short messages received by others all have Yan characters at the end. What's going on here?

I'll give you several operation schemes, and you can try them yourself, which should solve your current problems.

1) Try to borrow a mobile phone card and put it in your One V to send a message to see if it is normal. If it is "normal" after changing the card, it means that your SIM card is faulty; If the card is "abnormal" after changing, it means there is something wrong with your mobile phone.

2) It is recommended to check whether the third-party SMS software or management software related to SMS settings is installed in the mobile phone. Please uninstall all such software and try to send SMS after restarting your phone.

3) In order to troubleshoot the software, it is recommended to back up the mobile phone data and use it after restoring the factory settings.

4) This fault has nothing to do with the hardware of the mobile phone, and it is probably the fault of the mobile phone system. Please back up the information of your mobile phone, bring your invoice card and send it to HTC maintenance center for testing.