November 17 2017 Focused Inbox is finally coming to Outlook 2016 for Windows, in Version 1711 for all Office 365 Business/Enterprise subscribers and Outlook.com. The Targeted and Semi-annual builds provide Office customers a slower update path from Monthly. Users on the Targeted channel will have it in Outlook desktop in March 2018, while the Semi-Annual channel will get it in the semi-annual channel update released after March 2018.
Users seem to either love Focused Inbox or hate it and the ones who love it can’t wait to have it working in Outlook.
The delay is due to client-side requirements. Focused Inbox initially required Office 365 modern authentication be enabled and Outlook version 1703 or higher. Modern auth is now enabled by default on new tenants but if it was disabled by the administrator, users won’t have the focused inbox option in Outlook with version 1710 or older.
Starting with Version 1711 (build 16.0.8730), modern authentication is no longer a requirement and all Office 365 and Outlook.com users will have focused inbox capability in Outlook 2016 for Windows.
Also See "Using the Focused Inbox in Outlook Apps"
When the Focused Inbox is available in your account, Outlook will pop up a dialog alerting you to the new feature and ask if you want to use it.
If you are unfamiliar with the Focused Inbox, Outlook sorts your mail by what it thinks is important, classifying some mail (mostly bulk mail) as the less important, "Other". This is a special view, not a folder, and the mail remains in the Inbox.
The Focused Inbox in Outlook 2016 for Windows. (Click on All to select Unread)
The Focused Inbox in Outlook 2016 for Mac. In this mailbox, there are 3 new messages in the Other tab.
If you say Yes then change your mind, you can turn the Focused Inbox off from the View tab in Outlook for Windows or on the Organize tab in Outlook for Mac. It's also on the All menu (formerly By [field]) in Windows and on the By: [field] menu in Mac.
If messages are misclassified as either Other or Focused, right click on the message and choose Move to the [Focused or Other].
When Focused Inbox is turned off, the only tab you'll see is Inbox; Unread and Mentioned were removed as tabs but are on the All menu (and work with Focused Inbox enabled).