What is the yellow star on the top of the mobile phone?

I have been in this situation before. This is an unread message, but there is no message when you open the inbox, right? You must have installed some anti-virus security software with spam interception function. Is it? You access your security software and intercept rules and records. See for yourself, simple and clear. If these softwares are not installed, I can only say: "Format+restore factory settings.