Microsoft introduced a feature called Clutter, that will route emails that don't seem important to the user to another folder called​​ Other. This was a good approach to help users focus on emails that would be important to them, and they can check the​​ Other​​ folder later on, however, users needed to visit another folder in order to see emails. That's why Microsoft introduced​​ Focused/Other​​ filters.

Now in Office 365, emails will have 2 filter tabs,​​ Focused​​ and Other. Important emails are going to appear in the​​ Focused​​ tab, and​​ other​​ emails will appear the other tab clearly. Now a lot of questions might come up when using these features, so let's review some of them:​​ 

• How can a user control what emails appear in​​ other​​ and what emails appear in​​ focused​​ tab?​​ 

There are algorithms that teach the application what emails are good enough to appear in the​​ Focused​​ tab, so once a user moves an email from the​​ Other​​ tab to the​​ Focused​​ tab, Outlook will know that this email source is important for the user, and it'll make sure to make upcoming emails from this source appear in the​​ Focused​​ tab.

• Can a user disable​​ this whole functionality in his Outlook application?

Yes, you can do so by selecting the filter dropdown beside the tabs, and unchecking the option to "Show Focused Inbox", as​​ shown in​​ the image below:​​ 

Now let's have a look at this scenario, let's say you're working on a project inside SharePoint online, and one of your colleagues mentions you in the newsfeed inside that project portal, like the following image:​​ 

You're going to receive an email from:​​ no-reply@sharepointonline.com,​​ ​​ But .. That email is going to appear only under the​​ Other​​ tab, and here's the catch, you won't receive notifications for emails that appear under the​​ Other​​ tab. By notifications I mean, you won't get notified when you're working in Office 365 that you received a new email:​​ 

Remember that the newsfeed web part only sends emails when you're mentioned.​​ 

So how do you solve this? You can't just ask each employee to disable the​​ Focused​​ functionality. You have 2 options in this case, either tell Exchange Online to route all emails from no-reply@sharepointonline.com to the​​ Focused​​ tab, or you can just disable the​​ Focused​​ inbox functionality on the tenancy level. Here's how we can do that:​​ 

Go to your Office 365 Exchange admin center, and from the left navigation, click "mail flow". Click the + sign to add a new rule:​​ 

A new window will appear, that looks like this:​​ 

Give the rule a name, let's say: "Other to Focused Emails Routing", then choose "The recipient address includes…" and click "Enter words…" and add the address you want to appear under​​ Focused​​ tab for all users, in this case no-reply@sharepointonline.com, then click the + sign and hit​​ OK.​​ 

Then go all the way down and click​​ "More options…":​​ ​​ 

In the "Do the following…" dropdown list, choose:​​ Modify the message properties > set ​​ a message header

Set the header to:​​ X-MS-Exchange-Organization-BypassFocusedInbox​​ ​​ and the value to​​ true.​​ So the final result should be:​​ 

Click save, and that's it. You can wait for a couple of minutes, and then test it. Upcoming emails will be delivered to the​​ Focused​​ tab, and you will receive notifications.

The other option would be to disable the​​ Focused​​ inbox functionality for all users in the tenancy, which leaves you with PowerShell. Once you connect to Exchange Online using PowerShell, you can run the following 2 commands:​​ 

Get-OrganizationConfig

Set-OrganizationConfig -FocusedInboxOn $false

I prefer doing the first​​ approach, and just routing the important emails to users'​​ Focused​​ tab, and give them the freedom to have it if they need.​​