What is the reason for sending failed SMS?

There is a delivery report in the text message. As long as it is turned on, when you send a message to the other party's mobile phone, you will see a successful report. If it doesn't arrive (stop, etc. ), there will be no delivery report, and after a certain period of time, delivery failure will be displayed.

SMS Settings-Open the message report in the status settings, and after sending, you will be prompted: sending succeeded or failed.

However, it is said that Unicom Mobile's mutual report may be inaccurate. This feature is free.

If the other party replies to you, it also means that the other party received the message; If the sending of short messages fails, there will generally be a short message prompting that the sending is unsuccessful. Expansion: Mobile users can open the "short message receipt" service, and the monthly function fee is 2-3 yuan according to different regions. When the other party receives a text message, it will receive a text message reminder.

Data expansion

There are two kinds of short messages: one is text or digital information sent or received directly by users through mobile phones or other telecommunication terminals, and the number of characters that users can receive and send short messages at a time is 160 English or digital characters or 70 Chinese characters. One is MMS. Its biggest feature is that it supports multimedia functions and can transmit comprehensive content and information, including text, images, sounds, data and other multimedia formats.