How to Fix Outlook Cleanup Not Working Problem?

  

Published By Jamie Kaler 

Approved By Rollins Duke

Published On July 22nd, 2025

Reading Time 9 Min Read

Why Does This Matters?

• Duplicate Emails can clutter your inbox.
• Large Mailboxes reach size limits or slow down performance.
• Important Messages Buried under old or necessary threads.
• Wasted time spent manually organizing and deleting emails.

Why Does Outlook Cleanup Not Work?

• Outlook Cleanup Tool Not Working due to configuration or several technical issues. Know the common causes to resolve this problem:
• A corrupted Outlook user profile can prevent various features including cleanup not functioning properly. Creating a New profile often resolves multiple syncs and behaviour issues.
• Outlook struggles to process large volumes of emails, especially when the mailbox contains oversized attachments. This can cause the cleanup process to timeout or skip items
• If your Auto Archive is turned off or cleanup rules aren’t configured, Outlook may not perform any visible action when cleanup is triggered.
• Using older versions of Outlook can create compatibility issues and bugs. Microsoft offers frequent updates to get faster performance and stay bug-free Outlook.

Symptoms of Outlook Cleanup Not Working

• Cleanup tools run but no emails are deleted.
• Duplicate emails still appear after running the cleanup folder.
• Cleanup conversation skip entire threads.
• Error message no message was cleaned up.
• Archive items reappear or never remove.

Difference Between Clean Up vs Clean Up Old Items

Conversation Cleanup

This tool analyzes messages in a thread and deletes emails that are fully contained in later replies. Its deals for cleanup back and forth conversation quoted content.

Clean Up Old Items(Archive)

This feature moves emails based on range as you selected to consider as older email into an Archive folder. It helps reduce mailbox size but doesn’t remove duplicates or redundant replies.

Helpful Features of Recommended Software

• This software can also remove emails, contacts, calendars and extract duplicate attachments from Outlook.
• It offers a simple initiative interface to make it friendly to operate by all types of professional and individual users.
• You can also use Auto detect feature to detect Outlook file location and also use let me select feature to browse from any custom location.
• With this wizard, you can also use Advanced filters such as selective export settings for email duplication, date range. From, to, subject, saving folder naming, exclude empty folders, separate PST per user, change language, export only selected Outlook items, split PST file etc.
• This software also offers you to select the Outlook folder to remove duplicates from specific Outlook folders.

Fix Methods for Outlook Cleanup Not Working

If Outlook cleanup features are not working as expected, try the following proven solutions. These methods range from quick configurations fixes to deeper repair techniques are are designed to resolve the most common causes behind Outlook Clean Up Not Working:

Method 1: Disable Conflicting Rules and Add‑ins

Managing Rules & Alerts

1. Open Outlook and navigate to file and click on Manage Rules and Alerts.
   
2. Review all active rules and temporarily disable or delete rules that move, copy or flag messages automatically.
3. Run the Clean Up Tool again to check for improvement.

Disabling third‑party add‑ins

1. Navigate to file and click on Options then press on Add-ins.
   
2. At the bottom, select COM Add-ins and tap the Go button.
   
3. Uncheck all Microsoft Add-ins and relaunch Outlook and try the cleanup function again.
   

Method 2: Repair or Re‑create Outlook Data File (PST/OST/BAK)

Using SCANPST.exe

1. Navigate to C:\Program Files(x84)\Microsoft Office\root\Office16 and open SCANPST.exe.
   
2. Now, Select Outlook files as you wish to repair and press on the Repair button.
   

Creating a fresh PST/OST profile

1. Navigate to OST/default location: C:\Users\Admin\AppData\Local\Microsoft\Outlook\email.ost
   
2. Delete or rename it and relaunch Outlook to recreate Outlook files.

Method 3: Use Cleanup Tool Correctly

Steps to invoke Clean Up Conversation / Folder / Subfolders

1. Right-click on Message and tap on Clean Up Conversation.
2. Navigate to Home and click on Clean Up and press on the Clean Up folder.
   
3. Clean Up folder and subfolder same as above but includes nested folders.
   

When No Messages are Deleted (Outlook considers none redundant)

1. Message contains unique attachments.
2. Inline replies or altered content.
3. Messages outside the threads are manually moved.

Method 4: Manual Export and Re‑import Mailbox

Exporting to a new PST file

1. Navigate to file and click on open and export and hit on Import/Export.
   
2. Choose Export to a file and tap on Next button.
   
3. Select Outlook data file and select the desired folder.
   
4. Browse the destination path and press the finish button.
   

Deleting Duplicates in Original Mailbox

1. Use filters or sort by subject, date, to find and remove duplicate items.

Importing Cleaned File Back

1. Navigate to file and click on open and export.
   
2. Press on Import/Export and select Import from another program or file.
   
3. Select your cleaned.pst and choose not to import duplicates.
   

Method 5: Clean Up Old Items Not Archiving (if using Clean Up Old Items)

If you relying on Auto Archive and its not triggering cleanup, the issue might be in Outlook determines items age:

Registry tweak: ArchiveIgnoreLastModifiedTime

1. Press Win+R and type regedit and hit Enter.
   
2. Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Office\\Outlook\Preferences.
   
3. Create a New DWORD(32-bit) and named ArchivedLastModifiedTime.
   
4. Set its value to 1 and relaunch Outlook.
   

Advanced Troubleshooting Tips

If quick fixes doesn’t work then you can try advanced solution as we have shared in the upcoming section:

Solution 1. Run Outlook in Safe Mode to Isolate Add‑Ins

1. Press Win+R and type Outlook.exe/safe.
   
2. Try to use Outlook Clean Up Tool if it works then it happens due to Add-ins.
3. So, remove faulty Add-ins and continue using Outlook clean up Tool.
   

Solution 2. Reset Custom Views using Outlook.exe /cleanviews if interface glitches

1. Close Outlook.
2. Press Win+R and type Outlook.exe/cleanviews and hit Enter.

Solution 3. Compact OST or PST files to Reclaim Space

1. Navigate to file and click on Account Settings.
   
2. Tap on data files and hit on Settings.
   
3. Press on Compact Now.

Preventive Measures to Avoid Cleanup Failures

1. Auto Archive helps to reduce mailbox size by moving or deleting older data. To prevent issues Outlook cleanup Not Working make sure Auto Archive is enabled on a regular schedule and is set to target the appropriate folders. You can access these settings under file tap on options and click on Advanced and hit on Auto Archive settings.
2. The Outlook cleanup tool may not work when Outlook files are not managed in system folders. Regularly empty your deleted items and junk emails to free up space and reduce mailbox load, ensuring that cleanup operation runs smoothly without any delay.
3. Oversized attachments contribute significantly to mailbox bloat. To prevent cleanup failures store large files in OneDrive, SharePoint, or local folders instead of keeping them in your Outlook mailbox. This reduces files size and speeds up Outlook performance.
4. Outlook doesn’t automatically shrink files after deleted items. Use Mailbox Cleanup Tool to identify large folders, and compact your data files to reclaim storage. This keeps Outlook runs smoothly and maintains Outlook mailbox data.

Resolution

Let’s sum as we have shared all crucial information to fix Outlook Cleanup Not Working. We have shared quick fixes, advanced troubleshooting and also shared its alternative technique. As when users need instant results and don’t want to invest much time and effort. So, you can opt Alternative Approach and easily navigate and remove duplicate items from Outlook and get maintained results.