Microsoft announced on September last year that Focused Inbox, which separates priority messages from others, would soon be coming to Outlook on all supported platforms. According to the company, the feature, alongside other features announced at the time, would arrive either by the end of 2016 or in the first quarter of 2017.
Focused Inbox was already available for Android and iOS for quite some time and the company released it and a lot of other features to Outlook Mail on Windows 10 by the end of February 2017. Unfortunately, the desktop version of Outlook didn't receive the promised feature before the end of this year's first quarter.
But as spotted by Tony Redmond from Petri, Focused Inbox is now available for some Office users running Outlook 2016. As detailed in an updated article at the Office Blogs, all Office 365 users in the First Release program and approximately 25 percent of those in the Standard Release now have access to the feature, with the remaining 75 percent scheduled to receive it in the next 3-5 weeks.
Also, in order to have access to the Focused Inbox, it is necessary to be running Outlook 2016 build 16.0.7967.2xxx or later. Redmond himself only had access to the feature in late April after receiving build 16.0.8067.2032. You can check the look of Focused Inbox on Outlook 2016 in the image below.
Finally, Microsoft has stated that the web version of Focused Inbox is already available and set to "on" for almost all users in North America and to approximately 10 percent of users worldwide, even though for those it is set to "off" by default. The company is currently working on expanding the worldwide availability of the service in a default "on" state since March 2017.