Hi @Simona Stegmann Holst ,
I understand your concern. Unfortunately, as of now, it seems that the built-in "Report Message" feature in Outlook cannot be disabled. This is a decision from the Microsoft development team.
However, you can provide feedback to Microsoft about this issue. To do this, you can go to File > Feedback > Suggest a feature and input your suggestions. Many features of our current products are designed and upgraded based on customers’ feedback. With requirements like this increase, the problem may well be released in the future.
You can also check the Microsoft 365 roadmap to see if the feature you want to implement is already under development.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.