The blue message sent by the new number has been sent in the past. What happened?

The blue SMS sent by the new number has been sent, because the sent SMS has been successfully sent to the other party's mobile phone. The short message display has been delivered, which means that the receiver has successfully received the short message, and the number of the short message center will be included in the setting of the short message function in the mobile phone. When sending a short message, the short message is actually sent to the short message center first, and then sent to the specified number of users through the short message center, which is equivalent to passing through a transit station dedicated to processing short message data. Sending only means that the short message has arrived at the short message center, and delivery only means that the whole delivery process of the short message is successful.