If Focused Inbox is enabled for your organization, Clutter won't work. If you prefer to use Clutter over Focused Inbox, use the following steps.
1. Sign in to Outlook on the web.
2. At the top of the page, select the App launcher > Outlook
3. At the top of the page, select Settings, select Mail > Layout > Focused Inbox.
4.Refresh your browser.
5. On the navigation bar, return to setting and the Clutter options should now be available: setting > Mail > Automatic processing > Clutter.
6.Choose Separate items identified as Clutter > Save.
For More Information Visit
https://www.microsoftoutlookhelp.support/get-the-outlook-technical-support-to-disable-clutter-feature-in-outlook-with-expert-technicians/
Toll Free Number: +1-800-987-2301
By Sheryl Gupta