How to Remove Duplicate Emails from PST File?

Rollins Duke   
Published: May 10th, 2024 • 6 Min Read

User Query: Hi BitRecover Team, being an Outlook administrator, I have several PST files which have duplicate emails. I want to remove duplicate emails from PST files to get a better performance of Microsoft Outlook. Some of my PST files have approx 50 GB of data so I want to split PST files into small parts while deleting duplicates. I have tried to resolve my problem using the Clean Up feature but this is not effective for me. Do you have any professional software or service to delete duplicate emails in PST according to my choice?

– Rowan Davis, Florida USA

Expert Reply: Hi Rowan Davis, please don’t take any stress off, we have a complete solution available to manage Outlook PST files. BitRecover recently launched Outlook Duplicate Remover Software which is well suitable according to your concern. This tool gives the facility to remove duplicate emails from PST files with advance filters. Even it has a separate option to set the size for processed PST files like 2 GB, 5 GB, 10 GB, and 20 GB. You can use this software for performing several filtered duplicate removal tasks as mentioned below.

Now BitRecover is explaining the complete step-by-step process to remove duplicate emails from PST files by selecting the size. First, download and install the suggested software on your computer before performing. Let’s start now.

How to Delete Duplicate Emails in PST File?

  1. Start the tool and add PST files in the software GUI using manual and automatic options accordingly.
    add duplicate pst files
  2. Use near checkboxes to select email folders from which you want to delete duplicate emails.
    select pst folders
  3. Choose a preferred mode to search duplicate messages within and across the folders.
    two modes to remove duplicates within and across the folders
  4. Now choose pre-set the maximum size for resultant PST files as 2 GB, 5 GB, 10 GB, and 20 GB.
    choose pst file size
  5. After that, use advance filters to erase duplicate emails in PST files by date, email id, and email subject.
    advance filters
  6. Afterward, click on the Browse icon and set the destination path to store processed PST files.
    browse destination path
  7. Press the Extract button to start the process to remove duplicate emails in PST files.
    remove duplicate emails from pst file
  8. Now you can see the popup message of successful completion of the task.
    completed successfully
  9. Lastly, the software will automatically open the destination path so that you can easily get processed PST files.
    processed pst data

Other Alternatives to Remove Duplicate Emails from PST File

Microsoft Outlook also provides some alternative options to delete duplicate emails from PST files. Here, we are discussing all alternative options which can be helpful in such cases but there is no guarantee for a success rate. You can click on any alternative method and scroll down.

  1. Use Inbuilt Import/ Export Option
  2. Remove Configured Duplicate Accounts
  3. Use Clean Up Folder & Subfolders

1) Import/ Export Option to Delete Duplicate Emails from PST

  1. Run MS Outlook client and select Open & Export > Import/ Export option.
    import export
  2. Select Import from another program or file option and press the Next button.
    import from another program or file
  3. Choose Outlook Data File (.pst) option and click on Next.
    outlook data file
  4. Press the Browse button and choose a PST file from your pc that has duplicate emails.
    browse pst file
  5. Check the Do not import duplicates option and hit on Next to continue.
    do not import duplicates
  6. Select the Finish button to start importing emails with removing duplicates.

Note: Once your PST file is imported into Outlook without duplicates, then export it from Outlook if you want to reuse it somewhere else.

2) Check & Remove Configured Duplicate Accounts

Sometimes if Outlook stopped working due to the account settings, then users again set up a previously used email account with Outlook. That becomes the cause for PST duplicates and users may see the same emails twice. Let’s know how to fix them.

  1. Start Microsoft Outlook and select Info > Account Settings as shown in the below figure.
    account settings
  2. Choose Account Settings from the available drop-down options.
    add or remove accounts
  3. If you see a duplicate account is configured then select it and choose the Remove option.
    remove duplicate account

3) Use Clean Up Folder & Subfolders Option

  1. Run Microsoft Outlook and select an email folder that has duplicates.
  2. Thereafter, select the Home > Clean Up option as shown on the respective screen.
  3. Select the choice option to remove email duplicates such as Clean Up Conversation, Clean Up Folder, and Clean Up Folder & Subfolders.
    clean up folder and sub folder
  4. If you choose Clean Up Folder & Subfolders then all redundant messages in the current folder and its subfolders will be moved to the “Trash” folder.
    clean up folder
  5. Now click on the Clean Up folder option to continue cleaning the duplicates.
  6. Open the Trash folder and delete redundant emails permanently to get rid of PST email duplicates.

Get Answers to All Your Questions

Que 1: Which is the best technique to remove duplicate emails from PST files?

Ans: We have mentioned all available possible methods to delete duplicate emails from PST files. However, the above-suggested software is best in all conditions as this simple and guaranteed solution.

Que 2: What are the extra benefits of software that are missing in manual approaches?

Ans: The unique features of software are mentioned below:

  • Pre-define the maximum size for resultant PSTs.
  • Remove duplicate emails in PST by date range, email subject, and address.
  • Search duplicate emails within and across the folders.
  • Delete duplicates based on From, To, Cc, Subject, Body, Attachments, and Time.
  • Create PST folders in different international languages for Non-English Outlook.
  • Repair corrupted PST files and get a healthy output without duplicates.
  • Microsoft Outlook installation is not mandatory.

Que 3: Why do duplicate emails accumulate in PST files?

Ans: There are multiple possible reasons for duplicate emails in Outlook PST files:

  • Setup incorrect rules in the Outlook application.
  • Configuration of multiple duplicate email accounts.
  • Error while setup email accounts.
  • Slow internet and antivirus programs.
  • Allow duplicates to be created during import.

Que 4: Can I delete duplicate emails from PST file exported from Outlook 2021?

Ans: Don’t worry! The tool is compatible with PST files of Outlook 2021, 2019, 2016, 2013, 2010, 2007, 2003, 2002, 98, and 97. It supports both ANSI and Unicode PST files.

Que 5: What are the benefits to remove duplicate emails in PST files?

Ans: Removing duplicate emails from PST is beneficial because:

  • Free up storage drive space.
  • Increase the performance of Outlook.
  • Avoid search-related confusion.
  • Avoid Outlook corruption due to oversized PST.


One of our clients sent us an email to [email protected] to know the complete steps to remove duplicate emails from PST file. Then we decided to publish a detailed informative article with a professional solution. Additionally, we have also mentioned the 3 different manual approaches to delete duplicate emails in PST files. If you have any other doubts about this problem then feel free to contact us a round off the clock.