Office 365: Outlook Focused Inbox

By default, Office 365 Outlook will have a "Focused" inbox enabled, which attempts to show only messages addressed directly to you in one group and all other messages (like mailing list messages) in another. You can disable this option by via Outlook on the Web with the steps below.

The Focused Inbox separates your inbox into two tabs-Focused and Other. Your most important emails are on the Focused tab while the rest remain easily accessible-but out of the way-on the Other tab. This can be an inconvenience if you are accustomed to having all your email appear in one place until you decide to move them.

To Disable Focused Inbox in Outlook:

Login to Outlook
Select View
Select Show Focused Inbox. (The Focused and Other tabs will disappear from your mailbox.

Note:

If you do not see the Show Focused Inbox button your version of outlook may not include this feature yet. Future updates will include it.
If you have multiple PCs you will need to perform these steps on each one.

To Disable Focused Inbox on the Web:

Login to Outlook on the Web with your NetID and password at https://outlook.office365.com
Select View
Select View Settings
Select Mail > Layout
Under Focused Inbox, select "Don't sort my messages"

For more information about the focused inbox, including the above instructions with images, please view the information at the following link: Turn Off Focused Inbox