Unicom's mobile phone calls the index number, and after hanging up, it automatically sends a text message back to Unicom's mobile phone. What's the matter?

1. After dialing the fixed telephone of some companies, the company's SMS promotion is received on the mobile phone, which is called on-hook SMS;

2. Introduction of on-hook SMS service: On-hook SMS service is an advertising media that pushes personalized SMS content to Unicom customers. When the mobile phone number is dialed to Unicom's fixed telephone, after the call, you will receive a short message with preset content from the called customer. The content of the short message can be enterprise introduction, product introduction, promotion activities, holiday wishes and other information, or it can be a link to the enterprise mobile phone website.

3. SMS service is divided into basic version, call center version and network version, and the charges are different. Specific to the local Unicom company hang up SMS charging rules shall prevail.