Duplicate Remover Tools

Last reviewed on September 20, 2013

While you can remove duplicates by hand, these tools make it easier when there are a lot of duplicates.

The following pages are a collection of mail utilities for Microsoft Outlook that don’t fit any of the categories listed under More Information.

There is a separate page for each type of utility and those who don’t fit within the four main types of utilities are under Mail Tools for Outlook.

This page lists duplicate remover tools. Although some of these tools work only with the mail folders, many will work on any Outlook folder that contains duplicates.

Manually Remove Duplicates Outlook 2003 and up | | Duplicate Remover Tools

Manually Remove Duplicates from Outlook 2003 and up

To remove duplicates, you need to use a single line table view.

In an email folder using the default group view, click on the row of field names and deselect Show in Groups, then turn off the Reading pane or slide it to the right.

For email folders, all standard views use a table view and you just need to turn off grouping and move (or turn off) the reading pane to enable the single line view. In the calendar, choose Events or By Category view, or in Outlook 2010, the List view.

Single line list view in Outlook

With a single line view:
Choose the modified date in the field chooser dialog

  1. Right-click any column heading, then choose Field Chooser.
  2. In the Field Chooser, switch from the Frequently-used fields list to Date/Time fields, and then drag the Modified date field to the view to add it to the fields displayed.
  3. Click on the Modified column header to sort by that field.
  4. You should now see your Outlook items in reverse chronological order.
  5. Click on the first item you want to delete.
  6. Use the scroll bar to find the last item with the same modified date.
  7. Hold down the Shift key as you click on the last one. This selects all the items between the two selections.
  8. Press Delete to remove them all from the folder.
  9. Reset the view when finished.

This method works well with imported items or when you re-download messages left on the email server because you’ll have one set of items with the same modified date.

To remove duplicate holidays from the Calendar folder in Microsoft Outlook
How to remove duplicate imported items in Outlook (Microsoft KB Article)

Deleted Duplicated Email Video Tutorial

The steps for Outlook 2003 and up are basically the same, except for the menu commands to turn the reading pane off and on. The first half of the video was recorded in Outlook 2010, the second half in Outlook 2007.

To turn the reading pane off and on in Outlook 2010, go to the View ribbon and expand the Reading pane menu.

Tools in the Spotlight

Duplicate Posts Eliminator

Clean your Outlook folders of post items. Supports mailbox, PST, and Exchange public folders. Supports Outlook 2010 Enter code WD9BHK53 during checkout.

E-mail Duplicates Eliminator

Cleans up a single folder by either deleting duplicates or moving them to a separate folder. Duplicate Email Eliminator Across Folders is a version to find duplicates across multiple folders. Enter code WD9BHK53 during checkout.


1-Click Duplicate Delete

1-click solution to remove duplicate mails, contacts or calendar items. Merges contacts automatically, has an undo function and a configurable advanced mode. Version 3.03 Now supports Outlook 2010 (both 32 and 64 bit).

Accurate Outlook Duplicate Remover

Accurate Outlook Duplicate Remover(AODR) can find and remove all duplicate Outlook items automatically. It quickly removes duplicates from Contacts, Calendar, Tasks, Notes and Email folders in one click. You can select any folder for duplicate Removing. It helps you to use your Outlook much more efficiently. Free.

Anti-Dupe for Microsoft Outlook

Remove unwanted Outlook duplicate records with Anti-Dupe for Microsoft Outlook add-in utility. Anti-Dupe for Outlook scans and deletes duplicate Outlook duplicate appointments, contacts, emails and tasks based on pre-determined criterion set by Anti-Dupe. Trial version available.

Delete Duplicate Email

When you reuse an old .pst file with a POP3 account or synchronize with smartphones/PDAs, you can inadvertently create duplicate messages. With the Delete Duplicate Email add-in, you can quickly delete these duplicate messages with just one click of a button! Works with Outlook 2000-2013 32 and 64-bit and Windows 8.

Delete Duplicates for Outlook

Delete Duplicates for Outlook is a tool for deleting duplicate e-mails for Microsoft Outlook. Detect and remove duplicate messages, contacts, calendar items, tasks, journal entries and notes. Compare messages by content (Standard), by part of the content (Special) or by unique message-id's (Light). Compare attachments and/or embedded files, by name and/or by content. Compare duplicates across several mailboxes or in within the boundaries of individual mailboxes. Use Regular Expressions. Works with all Outlook versions, including Outlook 2010/2013 32 or 64-bit.

Duplicate Email Remover

Finds and removes duplicates, even if the messages appear in different folders. Delete, move, or copy duplicates to any folder. Mark duplicate messages with a flag. Search for duplicates in the same folder, or in different ones. Process duplicates in Public folders on the Exchange Server.

Duplicate Killer

Outlook duplicate remover add-in for Microsoft Outlook to find and remove duplicate contacts, emails, calendar items, tasks and notes automatically. Remove Outlook duplicates. Merge Outlook contacts and other items. Compare, assign category, flag and move duplicates to selected folders. Preview duplicate search results prior to processing. Duplicate Killer has Junk Contacts removal functionality, regarding contacts that have too little information. Duplicate Killer is compatible with the latest Windows 8 and Outlook 2013 (including 32 bit "Click to Run" Outlook version).

Duplicate Notes Eliminator

Clean up your Notes folder, especially if synchronizing with your PDA leaves a lot of duplicates. For Outlook 2000 and 2002. Enter code WD9BHK53 during checkout.

LBE Toolbox for MS Outlook

Multifunction utility to send individual messages to a list generated either from a text file or from criteria on the Contacts folder, remove large file attachments, remove duplicate contacts and messages, and perform a few other little chores.

Outlook Duplicate Items Remover

Free tool for removing duplicate items from Outlook folders. ODIR recognizes duplicates in Contacts; Calendar; Tasks; Notes and Email folders. Using ODIR is very easy: select a folder and click the button Remove Duplicate Items. ODIR scans the selected folder for duplicates and MOVES all duplicates found to a subfolder ODIR_duplicate_items. Version 1.2

Outlook Duplicate Remover

Outlook Duplicate Remover allows you to find and remove Outlook duplicates and junk contacts in one click. Search duplicate items and merge Outlook duplicates automatically. Remove Outlook duplicates, such as duplicate Email, duplicate Contacts and Calendar events and Junk contacts. It is an automatic software add-in for Microsoft Outlook without any settings to configure. Duplicate Remover is compatible with latest Windows 8 and Outlook 2013 (including Outlook "Click-to-Run" versions) as well as Outlook 2010, 2007, 2003, 2002 and Exchange Server Public Folders. Supports French and German languages.

Outlook Duplicates Remover

Removes duplicate items from Calendar, Tasks, Contacts, Notes, and mail folders. Free.

ReliefJet Essentials for Outlook

The updated version of ReliefJet Essentials for Outlook adds many new features including support for Quick Text with hotkeys and expandable macros. New utilities added like Add BCC to Messages and Redirect Messages. All utilities can be integrated with Outlook Rules. A command line tool for Outlook professionals and administrators is also provided. More than 70 tools and utilities are now included.


Online service to eliminate wasted time by merging, cleaning, and eradicating contact conflicts. Works with Outlook, Gmail, Yahoo, and Mac address books.

Stellar Phoenix Outlook Duplicate Remover

Clean up your Outlook mailbox from unwanted and duplicate emails with Outlook duplicate remover tool. This software works as an Add-Ins in Outlook and removes duplicates as per different time span and scan criteria. Customized operations like Mark as Expired or Flag, Delete Permanently, Copy to folder and more are also a notable feature of this software.

Next page >> Outlook 2002 and older

Written by

Diane Poremsky
A Microsoft Outlook Most Valuable Professional (MVP) since 1999, Diane is the author of several books, including Outlook 2013 Absolute Beginners Book. She also created video training CDs and online training classes for Microsoft Outlook. You can find her helping people online in Outlook Forums as well as in the Microsoft Answers and TechNet forums.

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