Is the test report sent by SMS useful?

Do not belong to the mobile network, such as Unicom mobile phone, PHS (that is, local telephone) and so on. As long as it is sent, there will be a report of "sent to * * *", but in fact, if the other party's signal is not good or has stopped or turned off, he did not receive the message at that time, and will not receive it until it is turned on or the signal is good, but it will not be sent back to the sender at this time. Generally, there will be an information report just after it is sent. At this time, the information report is. Don't believe it. It takes several seconds to send a short message to a mobile phone user, which is the delay of sending and receiving. Generally, it is accurate, but sometimes it is inaccurate, and it is still credible in most cases.

As for why you don't send a report when changing your mobile phone card, you can look at the settings of your mobile phone. Some mobile phones are in the SMS settings, and you can set whether to send a report or not.

To sum up, you sent him a report as soon as you sent him a text message. This report is inaccurate. It's impossible to know whether he received your message or not. You must find another way. I don't think he received it, because the mobile phone can't send short messages directly to PHS. How to get him to receive your message can tell you our experience: the mobile phone sends a message to PHS (that is, the local phone), and the number should be preceded by "106".