Microsoft has quietly rolled out a quartet of new rule actions for Outlook on the web and the new Outlook for Windows, closing a long-standing gap in automated email triage. The actions—Clear Categories, Clear Flag, Complete Flag, and Flag Message—allow users to set up server-side rules that manage the follow-up state and category labels of incoming messages, not just move them around.

The update, which appeared on the Microsoft 365 Roadmap under ID 543425 and was marked generally available on July 30, gives both everyday users and Microsoft 365 administrators a hands-off way to keep inboxes organized. Until now, Outlook rules in the modern clients could copy, delete, or route messages, but couldn’t touch a message’s flag or category fields. That meant plenty of manual cleanup after an automated workflow ran its course.

What’s New in the Rules Engine

The four new actions slot into the existing rule builder under Settings > Mail > Rules in Outlook on the web or the new Outlook for Windows. Here’s what each one does:

  • Flag Message: Applies a follow-up flag to any incoming email that matches your chosen conditions. For example, you can flag every message from your manager or any email with “urgent” in the subject line.
  • Complete Flag: Marks an existing follow-up flag as done. This is useful when a subsequent rule moves a message into an “Archive” folder—you no longer need that visual reminder of follow-up.
  • Clear Flag: Strips a flag entirely, regardless of its status. Think of it as a reset button for automated workflows where a flag is no longer relevant.
  • Clear Categories: Removes all category labels from a message. This is handy when a message leaves an active project queue and you want to shed its classification tags.

These actions are server-side, meaning they fire as soon as a message lands in your mailbox, before you even open Outlook. They work for Microsoft 365 work and school accounts—but not for third-party services like Gmail, Yahoo, or iCloud, which must be managed through each provider’s own rules.

Why This Matters for Your Daily Workflow

The practical payoff is consistency. Imagine a shared mailbox where the team flags every new customer inquiry. An administrator can create a rule that flags all inbound mail, then a second rule that clears the flag when a message is moved to the “Resolved” folder. Without the new actions, someone had to manually click “Mark Complete” or remove the flag after the move.

Power users who rely on categories to track project statuses get a similar boost. A rule can label emails from a client with a “Project Alpha” category, and another rule can strip that category once the email is forwarded to a completed-work folder. The inbox stays clean without additional mouse clicks.

For IT admins managing dozens or hundreds of mailboxes, the ability to push flag- and category-management rules via deployment scripts means a more uniform user experience. It also reduces the number of help desk tickets from users who forget to unflag or recategorize messages after they’ve been handled.

The Road to Automated Flagging

The new Outlook for Windows—often called the “Monarch” client—launched with a replay of many classic Outlook features, but its rule engine remained limited compared to the veteran desktop app. Classic Outlook has long supported flag and category actions via custom VBA macros, but those never made the jump to the web-centric successor. Microsoft’s answer has been to rebuild automation natively.

The journey wasn’t fast. Roadmap item 543425 originally listed a general availability target of February 2026. Development apparently accelerated, because the feature was marked “Launched” in July 2026. Microsoft’s own support documentation now includes guidance on using these actions, and community forums like Microsoft Learn have seen a spike in questions about enabling flags within folder rules—a telltale sign that the feature is live and users are experimenting.

It’s worth noting that the roadmap entry’s current description confusingly references “Microsoft Scout,” an unrelated AI agent. That discrepancy hasn’t been explained, but the feature’s presence in Outlook’s settings and the supporting documentation confirm the rule actions are what actually shipped.

What You Should Do Right Now

If you rely on flags or categories to triage mail, take 15 minutes to review your existing rules and consider adding the new actions.

Step-by-step:
1. Open Settings (gear icon) in Outlook on the web or new Outlook for Windows.
2. Go to Mail > Rules.
3. Click Add new rule or edit an existing one.
4. Choose a condition (e.g., “From” a specific person, “Subject includes”).
5. Under Add an action, select one of the new options: Flag message, Clear flag, Complete flag, or Clear categories.
6. If you’re stacking multiple rules, pay attention to rule ordering and the “Stop processing more rules” checkbox. A poorly placed “Clear flag” rule could erase a flag you wanted kept.

A few caveats:
- These rules are server-side and apply to the mailbox, not just your client. Test carefully in shared mailbox scenarios.
- The actions treat flags and categories independently. Clearing a category won’t touch a flag, and vice versa.
- If you manually flag a message, a later rule could clear it unintentionally. Audit your rule order to avoid surprises.

What’s Next for Outlook Automation

Microsoft has been steadily closing the functionality gap between classic Outlook and the new client. With flag and category rules finally in place, the next logical steps could include more granular category management (such as adding a specific category rather than clearing all) or rule actions that modify sensitivity and importance levels. The roadmap doesn’t hint at such expansions yet, but given that users have waited years for this update, the pressure to round out the feature set won’t ease.

For now, the message is clear: your inbox rules can finally handle the full lifecycle of a message’s follow-up state. If you’ve been holding off on migrating to the new Outlook, this might be the nudge that makes the switch feel complete.