How to Remove Duplicate Attachments from Outlook

  author
Written By Chirag Arora  
Anuraag Singh
Approved By Anuraag Singh 
Modified On June 21st, 2025
Reading Time 7 Minutes Reading

If you’ve duplicate attachments in Outlook, it may slow down the system, taking up unnecessary space, whether it’s caused by syncing errors or similar forwards, which indirectly affects Outlook’s performance. In this article, we’ll guide you on how to remove duplicate attachments from Outlook using simple methods, also explain how you can delete duplicate attachments in Outlook efficiently.

Why Do Similar Attachments Come in Outlook?

Before we understand how to delete duplicate attachments on Outlook, let’s know how they are caused:

  1. Repeated Forwarding or Replying: In a long-standing email thread, the same doc that starts as an attachment gets forwarded an unlimited number of times.
  2. PST File Imports: Repeatedly importing a duplicate PST file can create duplicates of emails and attachments.
  3. Sync Errors: Syncing between devices, email accounts, etc., can duplicate information.
  4. Outlook Rules or Add-ins: Rules or 3rd party add-ins can create similar duplicate attachments with automated processes when rules are not set up correctly.

Why are we Deleting Duplicate Attachments in Outlook?

Allowing duplicate attachments to build up over time can result in:

  • Increased Mailbox Size: These attachments take up the additional storage of your Outlook. As these duplicates are unwanted, they fill up the space very quickly and reach their storage capacity, which required to remove duplicate attachments in Outlook.
  • Slow Loading Times in Outlook: As your mailbox size increases with the increase of duplicates, it slows down everything that loads, which directly affects the productivity of Outlook.
  • Cluttered Inbox: It becomes more difficult to find important emails when your mailbox is filled with duplicate attachments, which leads to miscommunication or confusion.
  • Missing Critical Data: When performing a manual clean, there is a chance you’ll delete the wrong file or message.

3 Effective Fixes to Remove Duplicate Attachments from Outlook

These problems can be fixed by following both manual and automated solutions. These solutions can delete duplicate attachments in Outlook and allow you to have the best results and performance. The methods are:

  1. Sort and Identify Attachments Manually
  2. Use Outlook Search Filters
  3. Using Best Alternative Automated Tool

Let’s get to know them one by one

Method 1: Sort and Identify Attachments Manually

You can manually sort emails by subject or sender, then open similar emails to check for repeated attachments. Upon confirmation, you can delete any duplicate versions.

Steps:

  1. Navigate to the folder where you suspect duplicates (e.g., inbox or sent items).
  2. Sort by option (e.g. by subject or by size of attachment).
  3. Open each email manually, identify and remove any repeated attachments.

Pros:

  • It doesn’t provide any other installation in system to remove duplicate attachments in Outlook.
  • You have full control as you’ve to decide which attachments to keep or to delete, which also maintains 100% accuracy.

Cons:

  • This manual process is very time-consuming, as you have to eliminate them one by one.
  • It’s not practical to do for users who are working on large Outlook data files.

In this method, you can simply search duplicate attachments in Outlook by using filter like attachment type, name of the file, etc.

Pros:

  • These feature allows filtering the duplicate attachments by name, date, size, etc.
  • Quick identification of duplicates enables Outlook to get better results as well as performance.
Cons:

  • It still requires opening emails manually to avoid the risk of loss of data.
  • This process required some tech-related skills to operate to remove duplicate attachments in Outlook.

Method 3: Delete Duplicate Attachments in Outlook Using an Automated Tool

You can prevent the issues faced by using manual methods by choosing the best professional automated tool, which is SysTools Outlook Duplicate Remover. This tool allows you to remove duplicate attachments in Outlook very quickly, keeping original data intact, and gives the best result.

 
It’s most efficient, secure and reliable tool which maintains integrity while eliminating duplicate attachments in Outlook. Also, this professional alternative solution can Remove Duplicate Events in Outlook Calendar. Look below for more pros of this alternative solution:

Advantages to Eliminate Duplicate Attachments in Outlook Using this Alternative Solution

  • Reliable Accuracy: Detects exact and partial duplicates even across Outlook folders.
  • Fast Performance: Processes thousands of emails with attachments in a few clicks.
  • Safe & Secure: It keeps the original email data intact, which saves them from the risk of losing it.
  • Ease of Use: Created for all types of users, as it has a user-friendly interface.
  • Free Trial Available: To scan the duplicate attachments before deleting, take advantage of the demo version.

Steps to Remove Duplicate Attachments from Outlook by Using Automated Tool

Steps to use:

  1. Install and launch the Outlook Removal Duplicate Attachments Solution.
  2. install

  3. Click Add File & Folders to upload your Outlook mailbox files.
  4. add file

  5. It allows users to add files within folder or across folder.
  6. within folder

  7. Choose Destination to save the outcome file where you want.
  8. destination

  9. In select item types, choose mail, task, or journal options for removing duplicates.
  10. select item type

  11. Set Specific Duplicate Criteria, such as attachments.
  12. sepcific

  13. Click Next to delete duplicate attachments in Outlook.
  14. next

How to Prevent Duplicate Attachments in Outlook Using this Tool?

  • Don’t Forward Emails with Large Attachments Multiple Times

Forwarding the same email with attachments makes several unnecessary copies. When appropriate, share with file attachments from a cloud link to prevent scheduling storage use.

  • Use Compressed File Formats

Compress large and/or multiple files into a ZIP or RAR file format to send them. This decreases the size of the files. It also enables a more efficient attachment workflow and version control.

  • Regularly Clean Your Mailbox

Delete older emails containing repeated attachments to clean up storage space. In Outlook, there is a Clean Up tool as well as possible use of a duplicate remover tool to further assist with management.

Conclusion

To maintain a clean, organised, and fast-accessible mailbox, deleting duplicate attachments in Outlook is a must. Some manual methods work in some areas, but they aren’t practically accessible for handling large mailboxes, so in that case, you might need a reliable, accurate automated tool which allows you to remove duplicate attachments from Outlook which helps to prevent chaos and make your Outlook mailbox clutter-free.

Smart email practices and regular maintenance ensure your Outlook stays organised.

FAQs about Outlook Remove Duplicate Attachments

Q.1 Can I Delete Duplicate Attachments in Outlook without Removing Entire Email?

A. Yes, open email in Outlook, then right-click on the attachments, and you can just select “Remove Attachments” option to delete attachments.

Q.2 Can Outlook Automatically Delete Duplicate Attachments?

A. No, Outlook doesn’t have a built-in feature to remove duplicate attachments from Outlook. You might require the automated tool suggested above, which helps you to eliminate duplicate attachments automatically.

Q.3 How can I avoid duplicate attachments in the future?

A. You should avoid importing emails from PST files, and configure rules properly which allow you to prevent duplicate attachments in Outlook.

  author

By Chirag Arora

Chirag Arora is a seasoned professional who wears multiple hats in the digital realm. As a Digital Marketing Manager, he orchestrates successful online campaigns, optimizing brand visibility and engagement. Additionally, Chirag brings meticulous attention to detail to his role as a Content Proofreader, ensuring that every piece of content shines with accuracy and clarity.