Outlook Focused Inbox and the legacy Clutter folder
How Focused Inbox separates important mail from the rest, and what happened to its predecessor Clutter.
Outlook's Focused Inbox is the feature that automatically separates likely-important email from likely-noise — newsletters, bulk mail, low-priority threads — into two tabs in the inbox: Focused and Other. It's been the default in Outlook since 2017 and is still the right answer for most users.
How Focused Inbox works
When mail arrives at the mailbox, Exchange Online's machine learning model classifies it as Focused or Other based on:
- Past user behaviour — what the user reads, replies to, deletes, marks as junk.
- Sender reputation — bulk senders, automated systems, marketing platforms.
- Content signals — headers, subject patterns, recipient lists.
- Explicit overrides — users can move messages between Focused and Other, training the model.
The model is per-mailbox and adapts over time. Different users get different sorting based on their own habits.
Where Focused Inbox shows up
- Outlook for Windows (classic and new) — Focused / Other tabs.
- Outlook on the web — same.
- Outlook for Mac — same.
- Outlook mobile — same.
- Notifications respect the Focused / Other split on mobile (Focused gets a notification, Other doesn't, by default).
Users can turn off Focused Inbox per-client and just see a single inbox.
The legacy Clutter folder
Before Focused Inbox, Microsoft had Clutter — a server-side feature that moved likely-unimportant mail into a Clutter folder rather than splitting the inbox into two tabs. Clutter was retired in 2020 and replaced by Focused Inbox. Mailboxes that still have a Clutter folder from the old era have it as a regular folder, no longer automatically populated.
Admin controls
Focused Inbox can be configured tenant-wide via PowerShell:
- Default-on or default-off for the tenant.
- Per-user enabled / disabled via Exchange Online PowerShell.
- Override policies that prevent users from changing the setting.
For most tenants, leaving Focused Inbox on by default with users able to opt out works well. Users who don't want the split turn it off; everyone else benefits.
How it differs from Junk Mail
Junk Mail is a separate filter — server-side anti-spam from EOP that moves likely-spam into the Junk Email folder. Focused Inbox is post-spam-filter classification: it works on mail that has already cleared the spam filter, sorting wanted-but-low-priority mail away from likely-important mail.
A bulk newsletter sender that's legitimate goes to Other. A phishing attempt goes to Junk (or quarantine). They're complementary, not redundant.
Tips for getting good Focused-Inbox sorting
- Train the model — move messages between Focused and Other deliberately for the first few weeks.
- Unsubscribe from genuine junk rather than leaving it to Other forever.
- Senders you'll always want in Focused — add to your contacts.
Focused Inbox is one of those quiet features that gets better the more you use it. The instinct to turn it off in the first week is often regretted.