Extension number, cloud horn, can you send text messages?

The extension number can't be used, and the cloud horn can send text messages. According to the query related information, the extension number and the SMS of the host are independent, and the SMS can only be received if certain functions are turned on. Cloud Horn is a courier notification APP that helps couriers automatically call and send text messages to inform users to pick up express mail. The mobile phone can send short messages without turning off the phone, stopping the phone, and not transferring calls.