If someone sets the flight mode to send him a message, does it not show delivery?

Of course not, because the signal is off.

The flight mode of mobile phone is also called aviation mode and flight mode. After the airplane mode is turned on, the GSM/GPRS module of the mobile phone will stop working. At present, there is no industry standard about flight mode in the mobile phone industry.

Some mobile phones have this function, and some can be realized by some software, such as the aviation mode in the system tools in S60 software. This mode can turn off the function of the SIM card, and the flight mode makes the mobile phone in a state of not receiving and sending signals without affecting other functions of the mobile phone (generally, the mobile phone cannot operate without the SIM card).

When the GSM/GPRS module of the mobile phone is turned off in flight mode, the mobile phone will not actively send paging signals to the base station, that is, it will not try to contact the base station, but it can generally make emergency calls (similar to the principle of no sim card, in this mode, the mobile phone can generally make international calls of 1 12, and may not support1/20, etc.

Because the paging signal of mobile phone will interfere with the electronic equipment on the plane, it is not allowed to turn on the mobile phone on the plane. In this mode, the related functions of mobile phone signal are turned off, and the mobile phone can continue to use other functions, such as looking up the phone book, enjoying articles, watching movies, playing games, etc., so it is called flight mode. Most of the power of the mobile phone is consumed by the signal. Turning off the signal in flight mode is very energy-saving.