How to Delete Duplicate PST Folder Set With Same Content Without Losing Data

admin | February 18th, 2019 | outlook

“After launching Outlook application on my PC, I found all my personal folders had disappeared mysteriously. Immediately, I started alarming and tried all the tricks before eventually closing and reopening my Outlook program. And then, I found all my folders had returned. But, the problem is that some of the folders have been duplicated and I cannot remove duplicate emails from Outlook 2016. Can someone suggest me why this is happening and how to delete duplicate PST folder set with same content?”

Duplicate folder / emails issues in MS Outlook (Outlook 2019, 2016, 2013, 2010, 2007, 2003, 2002, 2000) are very annoying as they increase the number of unnecessary emails and slow down the system performance. Basically, this happens due to some specific mail profile corruptions. Most of the time duplicate folder issues happen after upgrading Microsoft Outlook and the PST files get overwritten or replaced. In order to enhance the system and account performance, it becomes essential to eliminate Outlook duplicate folders (emails & other items like contacts, calendars, tasks, notes, journals, etc.) to free up extra occupied space by replicated files/ folders. This can be done via recreating the Outlook mail profile.

As this solution can be intense if the user is having a complex mail profile configuration. Hence, before doing this, one can try some other simple fixes to delete duplicate PST folder set with same content from Outlook account.

Reasons Behind Generating Duplicate PST Folder

There may several consequences of duplicate PST folder set with same content such as poor system performance, exceeded storage limit, data loss or corruption etc. But, what causes the duplication of emails in Outlook account? And how we can remove duplicate emails from Outlook 2016, 2013, 2010, 2007, 2003, 2002, 2000 versions without any data loss.

  • Receiving duplicate emails in Outlook from different companies. Some repeatedly send the same newsletters or emails at times
  • If ‘Leave Messages on the Server’ option is enabled in Outlook, it automatically generates multiple replicas of the same emails
  • Continuous synchronization of Outlook emails with multiple laptop or mobile devices also can result in duplication
  • Sometimes, anti-virus programs also create duplicates of email messages saved in Outlook PST (personal folder file)

Note: To Remove Duplicate folders and emails, User can use Outlook Duplicate Remover Tool. To Extract attachment from a PST file, you can use Outlook Attachment Extractor.

Methods to Delete Duplicate PST Folder Set With Same Content

Method 1. Open Outlook With Cleanprofile Switch

Launching MS Outlook application (Outlook 2007 / 2003 / 2000) with the cleanprofile switch is a simple way to remove duplicate emails from Outlook 2007 & below versions. It is so because doing this will remove invalid Registry Keys from Outlook mail profiles and recreate all the missing ones. Below is how to do this:

In Windows Vista and Windows 7

  • Click on Start button and type outlook.exe / cleanprofile

In Windows XP

  • Click on Start and open Run. Type outlook.exe / cleanprofile

Note: The above command is no longer supported by Outlook 2010. So this method is not available to remove duplicate emails from Outlook 2016, 2013 or 2010.

Method 2. Rename and Copy Outlook Folder

This is another simple way to eliminate or delete duplicate PST folder set with same content from Outlook folders. In this, you need to close Outlook application (MS Outlook 2019, 2016, 2013, 2010, 2007 etc.) and rename your original PST file. Then, create a copy of PST file and enter a different name for it. For example:

  1. The name of your original PST file is outlook.pst
  2. Now, rename this file to outlookA.pst
  3. After this, copy this PST file and rename it to outlookB.pst

Thereafter when you launch Outlook 2016 or below version application, it will prompt you for a new location. Locate it to outlookA.exe and after prompting again, locate it to outlookB.pst. In addition, you can attempt to disconnect the outlookB.pst file from MS Outlook as usual.

Method 3. Check Settings of Outlook Account

  1. Launch MS Outlook on your local machine
  2. Navigate to File and select Info >> Account Settings
  3. In the Account Settings window, click on Mail tab and perform a search for configured account name
  4. In case, if the account is configured with the same name more than one time then, you need to remove extra account via clicking on Remove
  5. Hit the Close button and the duplicate account will be removed after this


Duplication of emails and other items can create great confusion for users and lessen the work efficiency. Thus, it becomes necessary to remove duplicate emails from Outlook 2016, 2013, 2010, 2007, 2003 etc. to make Microsoft Outlook work normally again. In this technical guide, we have discussed the issues that occur after Outlook folder duplication in a profile along with their solutions to delete duplicate PST folder set with same content from Outlook PST file mailbox.