Why do people always get several messages when iphone sends them?

1. The sender did not receive the response from the SMS Center after sending the SMS, and the sender sent the SMS again, resulting in the receiver receiving multiple SMS messages.

2. The sender successfully sent the short message, but the receiver didn't respond when receiving the short message from the short message center (maybe the network environment was bad and the short message was lost), so the short message center may send the short message to the receiver repeatedly.

3. Both the receiver and the sender have the problem of short message function, that is, the short message function is not done well, so there are many possible reasons, so I won't list them one by one.