I sometimes get an imessage prompt on my Apple phone: Your operator may charge for the SMS used to activate imessage.

IMessage is a tool for Apple devices to send messages (short messages) through the network for free. Generally, iMessage needs to be activated before it can be used. Sending international SMS activation is one way, and the solution is as follows:

1. First, in the mobile phone, open the settings, as shown in the figure below.

2. Then in the settings page that opens,? Slide down to find "Info" and click Open, as shown in the figure below.

3. Then in the open page, click iMessage to close, as shown in the figure below.

4. Reopen the contact to send SMS, and a green "arrow" will be displayed to indicate that SMS can be sent successfully, as shown below, and the problem will be solved.