What's the exclamation point in Apple 13 SMS?

Some friends will find that when using the iPhone, there is always a red exclamation mark at the top right of the information application icon. So what is the exclamation point in Apple 13 SMS? Let's take a look ~

What is the exclamation point in Apple 13 SMS? Apple 13 SMS has an exclamation point for two reasons: the message failed to be sent and the iMessage message was not opened. For example, if the iMessage information is not turned on, the solution is as follows:

1. Open phone settings, and then click information options.

2. On the information setting page, just turn on the switch on the right side of iMessage information.

After returning to the desktop, you can see that the exclamation mark on the SMS of Apple 13 has been removed.

This paper takes Apple 13 as an example and applies it to ios 15 system.