With the new function release on Outlook “Focused Inbox” will substitute the “Clutter” function.
Focused Inbox for Outlook – Office Support
Check out this video for a brief overview.
How does Focused Inbox work?
Focused Inbox works with you to prioritize what’s most important. What lands in Focused Inbox is based on the content of the email (e.g., newsletters, machine-generated email, and so on) and who you interact with most often. If you need to fine-tune your Focused Inbox, Move to Focused and Move to Other options are available to do that.
Focused Inbox was first released on Outlook for iOS and Android. All versions of Outlook that receive updates will soon become Focused Inbox capable, including Outlook 2016 for Windows, Outlook 2016 for Mac, Outlook on the web, and Mail for Windows 10. You’ll see Focused Inbox once your Office 365 or Outlook.com mailbox is enabled for it.
Continue reading to how to do it at – https://support.office.com/en-gb/article/Focused-Inbox-for-Outlook-f445ad7f-02f4-4294-a82e-71d8964e3978?ui=en-US&rs=en-GB&ad=GB