iPhone message icon shows a red explanation mark on home screen.

Hi jens0117,

What you're seeing likely indicates there was an issue sending a message in the Messages app. Check your message threads, and use this resource as a guide for steps on how to resolve the issue: If you can't send or receive messages on your iPhone or iPad.

If you see a red exclamation point

1. If you try to send a message and you see  with an alert that says Not Delivered, follow these steps:

2. Check your network connection.

3. Tap , then tap Try Again.

4. If you still can’t send the message, tap , then tap Send as Text Message. Messaging rates may apply. Contact your carrier for more information.

Cheers.