Is there a charge for texting and starting to report? If so, how much is it?

Many mobile phones have the function of informing the other party whether they have received the short message. From k7 alone, there are only two settings: "Request reply" and "Send report".

When "Request for reply" is turned on, the other party cannot see whether to reply to the sender's notice in the received short message, let alone how to reply that the sender has received it. (seems to need network support)

Turning on "send report" literally means a notice to remind whether the short message has been sent, and it does not prove whether the recipient has read it. (That's what the customer service explained.)

According to my test, both sides are mobile. When the other party shuts down, K7' s message has been sent without prompting. Once the other party is turned on, this prompt will be prompted in time. It shall be deemed that the other party has read the notice.

When one party moves and the other party is connected, regardless of whether the other party is turned on or not, the words "message has been sent" are prompted, and it is impossible to judge whether the other party has read the short message.