In Outlook 2016 for Windows, "Clutter" can help you filter low-priority email, saving time for your most important messages. The email server keeps track of the email you read and the ones you do not. Once you turn it on, Clutter is automatic. As new email comes in, it takes messages you're most likely to ignore and puts them into the "Clutter" folder. The more you use it, the better it gets. And if you find Clutter isn't for you, you can turn it off.

Note: If you bought Office 2016 for Windows as a one-time purchase, and you do not have an Office 365 subscription, you will not have access to some features, such as Clutter. Going forward, there will be regular updates with new features where you’ll need to have an Office 365 subscription to use them.

Turn Clutter on or off

You need to turn on Clutter in Outlook Web App, so that you can use it both in Outlook Web App and Outlook.

  • Sign in to Outlook Web App at
  • At the top left corner of the page, select the App launcher icon, and then select Mail.

  • On the top right corner of the page, go to Settings  > Options > Mail > Automatic processing > Clutter.
  • Choose Separate items identified as Clutter, then Save.

    You can turn Clutter off anytime by unchecking Separate items identified as clutter.

    Note: The Clutter folder remains in Outlook after you turn off the Clutter feature.

Help Clutter Learn Your Preferences Faster

It might take Clutter a few days to fully adapt to your preference, as the system records your choices and uses the information to identify similar messages in the future. But you can help Clutter learn your choices faster:
  • If you see a low priority email in your Inbox, right-click the message and choose Move to Clutter, or drag the email from your Inbox and drop it into the Clutter folder.

  • If you see a message that was sent to Clutter by mistake, right-click the message and choose Move to inbox, or drag the email from the Clutter folder and drop it in your Inbox.

    Note: Moving an email in or out of the Clutter folder, from any of your devices, is enough to give the signal to the Clutter system that an item is Clutter or not. For example, if you move an email to the Clutter folder in Outlook desktop, or the Mail app on your phone, the action gets recorded in the Clutter system on all your mail apps. You don't have to do this individually in each app.

How Clutter filters messages

Clutter and junk email are both filtered out before they reach your Inbox. Junk email is evaluated and filtered first, then Outlook processes the rules (if you have set up any). Next, Clutter analyzes the remaining messages and filters out the types of messages that you usually ignore or don't respond to, based on your past behavior.

  • Messages from certain people will never be identified as clutter:
    • You
    • Anyone in your management chain
    • Your direct reports
  • Clutter looks at various aspects of messages to understand what you do not typically read, for example:
    • The sender
    • Whether you have participated in the conversation
    • If you are the only recipient
    • The importance

As your reading habits change, Clutter learns and adapts.

Manage the Clutter folder in Outlook

If you have Outlook 2016 for Windows, you can right-click the Clutter folder and choose Manage Clutter.

You will be directed to Outlook Web App to manage your Clutter options.

Applies To: Outlook 2016, Outlook 2013, Office 365, Office 365 Admin, Office 365 Small Business Admin, Outlook Web App for Office 365, Outlook Web App for Office 365 Small Business, Outlook on the web for Office 365 Business, Outlook Web App.