Classic Outlook to New Outlook: Rules – What simple rules can do and what advanced rules cannot

When you switch from Classic Outlook to the new Outlook for Windows, your rules move with you but not all rule types work the same way. Simple rules that move, flag, or forward messages based on sender or subject still function as expected. Complex rules that rely on server-side actions, custom scripts, or specific conditions may stop working or fail to run. This article explains which rules survive the migration, which rules break, and what you can do to keep your email automation running.

How Outlook Rules Work in Classic vs New Outlook

In Classic Outlook, rules run either server-side (Exchange Online) or client-side (on your local PC). Server-side rules process messages before they reach your inbox and work even when Outlook is closed. Client-side rules run only when Outlook is open and require the desktop app to be running.

The new Outlook for Windows is a web-based wrapper around Outlook on the web. It does not support client-side rules at all. When you sign in to new Outlook for the first time, it syncs your existing rules from Exchange Online. Any rule that was marked as client-only in Classic Outlook will not appear in new Outlook. Rules that were server-side will appear but may show a warning if they use an action that new Outlook cannot execute.

Simple Rules That Work in Both Versions

Simple rules use one or two conditions and one standard action. These are fully supported in new Outlook:

• Move messages from a specific sender to a named folder
• Flag messages that contain specific words in the subject
• Forward copies of messages to another email address
• Delete messages from a mailing list
• Mark messages as read after delivery
• Categorize messages based on the recipient address

These rules rely on Exchange transport rules or server-side processing, which new Outlook can read and apply.

Advanced Rules That Do Not Work in New Outlook

Advanced rules include any action that requires local processing or a desktop component. The following rule actions are not supported in new Outlook:

• Run a script
• Play a sound
• Show a desktop alert
• Display a specific message in a new window
• Move messages to a public folder that is not mapped to your mailbox
• Assign a category based on a custom property that is not indexed by Exchange

If you had a rule that ran a VBA script to move attachments to a local drive, that rule will be disabled in new Outlook. The rule may still appear in the rule list but will show a yellow warning icon indicating it cannot run.

Steps to Migrate Your Rules from Classic to New Outlook

Before you switch to new Outlook, follow these steps to preserve your rules and identify which ones will break.

1. Open the Rules dialog in Classic Outlook
   Select File > Manage Rules & Alerts. Click E-mail Rules and wait for the list to load.
2. Export your rules to a file
   Click Options and then Export Rules. Save the .rwz file to your desktop. This file is a backup of all rule definitions.
3. Review each rule for client-only actions
   Double-click a rule and look at the bottom of the Rules Wizard. If the rule description includes “on this machine only” or references a local script, that rule will not transfer.
4. Switch to new Outlook
   Open new Outlook by toggling the Try the new Outlook switch in Classic Outlook. Sign in with the same Microsoft 365 account.
5. Verify your rules in new Outlook
   In new Outlook, select View > View Settings > Rules. Compare the list against your .rwz file. Any rule missing or showing a warning icon needs to be rebuilt.
6. Rebuild unsupported rules using server-side alternatives
   For rules that used Run a script, create a Power Automate flow that performs the same action. For rules that played a sound, remove that action and keep only the server-side actions.

What Happens to Rules After You Switch Back to Classic Outlook

If you switch back to Classic Outlook after testing new Outlook, your rules may appear duplicated or corrupted. Each time you toggle between the two versions, Outlook re-syncs the rule set from Exchange. Client-only rules that were disabled in new Outlook may still be present in Classic Outlook but could show a warning that they were modified. To avoid data loss, always export your rules before switching versions.

Rules Created in New Outlook That Do Not Appear in Classic Outlook

New Outlook creates rules as server-side Exchange rules. When you go back to Classic Outlook, those rules should appear. However, any rule that uses a condition unique to new Outlook, such as a filter based on a specific message header that Classic Outlook does not expose, will not show up. In practice, this is rare because both versions use the same underlying Exchange rule schema.

Common Issues with Rules After Migration

Rules Are Missing from the List in New Outlook

Open your .rwz file in a text editor to see the rule names. If a rule is missing, it was likely a client-only rule. Check the rule description in the .rwz file for the string on this machine only. If found, you must recreate that rule using server-side actions or a Power Automate flow.

Rules Run but Do Not Move Messages to the Correct Folder

In new Outlook, folder names are case-sensitive and must match exactly. If your rule referenced a folder named “Newsletters” but the actual folder is named “newsletters”, the rule will fail. Edit the rule in new Outlook and select the folder from the folder picker to ensure the correct path.

Rule Shows a Yellow Warning Icon and Does Not Run

The warning icon means the rule contains an action that new Outlook cannot execute. Open the rule and remove any unsupported actions such as play a sound, show a desktop alert, or run a script. After removing the unsupported action, save the rule and it will start running.

Item	Classic Outlook	New Outlook
Rule execution	Server-side and client-side	Server-side only
Move to folder	Works for any folder	Works for any folder
Run a script	Supported	Not supported
Play a sound	Supported	Not supported
Desktop alert	Supported	Not supported
Forward to another address	Supported	Supported
Automatic reply (out of office)	Not a rule action	Not a rule action
Rule priority	Ordered list in Rules Wizard	Ordered list in Settings
Export format	.rwz file	No export option

Now you know exactly which rules will survive the move from Classic Outlook to new Outlook and which ones need a replacement. Start by exporting your current rules using File > Manage Rules & Alerts > Options > Export Rules. For any rule that used a script or desktop alert, set up a Power Automate flow to handle that task instead. Test each rule individually after switching to new Outlook to confirm it triggers correctly.