Is SMS a negotiation back to an A in a group?

The text message negotiated back to A is sent in packets.

Mass texting is a common way of information exchange and transmission in our daily life. For example, enterprises can send promotional messages and blessing messages to customers during festivals, and do a good job of customer communication through SMS in daily life.

The format of mass SMS is generally SMS signature+title+content, but there are three sections: SMS signature, title and content.