October 2026 · Folder Suggest

Outlook “Error Reading the Rules from the Server”: How to Fix It

Classic Outlook opens Rules and Alerts, shows an empty list and says the format of the server rules was not recognized. Your rules are not gone. One of them is stored in a form classic Outlook cannot read, and the fix is to find that one.

The message “There was an error reading the rules from the server. The format of the server rules was not recognized.” is a known issue in classic Outlook for Windows that Microsoft lists as under investigation, with no fix yet. It appears after a rule has been changed, the next time you open Rules and Alerts. Your rules are still in your mailbox: Outlook on the web shows them, and server rules keep running. The quickest fix is to open Outlook on the web, delete the rule you created or edited most recently, restart classic Outlook, and recreate that rule on the web. If that does not clear it, Microsoft’s own workaround is to delete all rules and add them again, either on the web or with outlook.exe /cleanrules.

What the Error Means

Outlook keeps most rules in your mailbox on the mail server, so they can run when Outlook is closed. Classic Outlook downloads that rule set whenever you open Home > Rules > Manage Rules & Alerts. If one rule in the set is saved in a format it does not understand, it refuses the whole set. The list comes up empty, and the message appears once, or in some reports a dozen times at every start.

Nothing has been deleted. The new Outlook and Outlook on the web read the same rules without complaint, which is the first thing worth checking: if your rules are listed there, you are looking at this problem and not at lost rules.

Why It Happens

In Microsoft’s description of the issue, the error follows changes to rules in classic Outlook. The sequence Microsoft gives involves a rule with the Display a Desktop Alert action, which saves the rule in a newer version, followed by later edits or copies of rules. Microsoft also says this may not be the only cause. In the reports on Microsoft’s community forum, the trigger is almost always the rule created or edited last before the error started.

This is a different error from “One or more rules couldn’t be uploaded to Exchange server and have been deactivated”, which means a rule is client-only or the mailbox is over its rules quota. That one is covered in why Outlook rules keep turning off.

Before You Delete Anything

Every fix below deletes at least one rule, so make a note of what your rules do first. Classic Outlook cannot show them while the error is up, and its Export Rules option exports the empty list it can read. Open them in Outlook on the web instead (Settings > Mail > Rules) and copy down each rule’s conditions and actions, or take a screenshot of each one.

Fix 1: Delete the Most Recent Rule in Outlook on the Web

This is the fix that has worked for most people who reported it, and it keeps your other rules.

Sign in to Outlook on the web (or Outlook.com for a personal account).
Go to Settings > Mail > Rules.
Delete the rule you created or changed most recently before the error began.
Close classic Outlook completely and open it again, then open Manage Rules & Alerts.
If the list now loads, recreate the deleted rule in Outlook on the web, not in classic Outlook.

If the error is still there, the culprit is another rule. Delete the next most recent one and restart again. Once the list loads in classic Outlook, recreate the deleted rules on the web.

Fix 2: Delete All Rules and Add Them Again

This is the workaround Microsoft gives, and it always clears the error because there is nothing left to misread. There are two ways to do it:

On the web: in Outlook on the web, Settings > Mail > Rules, delete every rule.
With a command: close classic Outlook, press Windows + R, type outlook.exe /cleanrules and press Enter. Outlook starts with no rules at all.

/cleanrules removes server rules and client-only rules alike, and it acts on the mailboxes in your Outlook profile, so if the profile also opens a shared or second mailbox, check that mailbox’s rules afterwards. It does not touch email or folders.

Then recreate your rules from your notes, in Outlook on the web where you can.

What Does Not Help

Quick Repair or Online Repair of Office. People who tried both on Microsoft’s forum still had the error. The problem sits in the rule data in your mailbox, not in the installed program.
Re-enabling or editing rules in classic Outlook. It cannot show them, and editing there is how the bad rule usually got saved.

Keeping It from Coming Back

Create and edit rules in Outlook on the web or the new Outlook. They only offer actions the server can run, so they cannot save the kind of rule that triggers this.
Leave out Display a Desktop Alert and other client-only actions unless you need them. A rule with one of those runs only while classic Outlook is open anyway. See client-only vs server-side rules.
Keep the rule set small. Fewer rules means fewer to check when one breaks, and less of the mailbox’s rules quota used. How many Outlook rules you can have explains the limit.

Rules break because a filing system built from them is a set of instructions you have to keep correct. Folder Suggest works the other way: it reads each email and suggests the right folder from the folders you already have, so there is no rule set to corrupt. It runs on your own computer, in classic Outlook, the new Outlook, Outlook on the web and Mac, and it is free to start.

Add to Outlook

Frequently Asked Questions

Have I lost my Outlook rules?
No. The rules are stored in your mailbox on the server, and Outlook on the web and the new Outlook still show them. Rules that run on the server usually keep filing mail while the error shows. Only classic Outlook for Windows fails to read them.

Does outlook.exe /cleanrules delete my emails?
No. It deletes rules only, both the ones stored on the server and the client-only ones on that computer. Your email and folders are untouched. Write your rules down first, because every one of them is removed.

Does this error happen in the new Outlook?
Microsoft describes it as a classic Outlook problem. The new Outlook and Outlook on the web read the same rules without the error, which is why they are the place to find and delete the rule that caused it.

Why did the error come back after I fixed it?
The rule that triggers it was probably recreated in classic Outlook the same way. In Microsoft’s description the error follows a rule that uses the Display a Desktop Alert action and is then edited or copied. Recreate rules in Outlook on the web, which cannot add client-only actions, and leave desktop alerts out.