Remove MS Outlook Duplicate Emails

Duplicate items in the Outlook mailbox are redundant and allow PST files to grow unnecessarily. MS Outlook add PST file with a specific storage capacity in the local drive. The email storage limit of a PST file depends upon the MS Outlook version that you use. For example if you use MS Outlook 2002 or older version, then PST file can hold your outlook mailbox items up to 2 GB only. Therefore, you need to check and remove redundant items from your Outlook mailbox very frequently, so that PST file of your mailbox does not exceed the 2 GB limit. Oversized PST files will block your mailbox data for access. Outlook 2003, 2007, 2013 and 2010 offer large PST storage capacity and therefore, chance of PST corruption due to duplicate emails become quite less with these versions. But email transaction in your Outlook mailbox will get slower due to accumulation of duplicate emails, contacts and other data.

Software Features

Remove duplicate emails in outlook items precisely and safely

Duplicates email items can be deleted permanently, marked as expire, moved to ‘Deleted Items’ folder, just marked read and flagged, copied to sub folder, moved to sub folde

Helps in reducing PST file size by removing duplicates

Allows to select any number of mailbox email folders at a time for detecting duplicates

Provision of selecting time range of messages and posts for scanning and detection of duplicates

Looks for email duplicates in terms of similar text, subject, sender email, sender name, receiver name, internet header, date and time of sending, as duplicates

Provision of saving compared or duplicate results either in .CSV format or .HTML format

Duplicate outlook emails and contacts may also adversely affect email communication in the large business organizations that make use of MS Outlook client. Therefore, it is quite imperative to take corrective steps so that Outlook mailboxes or PST files does not grow very large. You can remove duplicate outlook data either manually or automatically. If you want to remove duplicate emails and contacts of your Outlook mailbox manually, here are steps that you need to follow:

  • Open your MS Outlook profile
  • Click Outlook folders one by one and delete matching records from individual folder
  • Disconnect your mailbox from Exchange Server if it is configured on the mail server
  • Click File> Data File management
  • In the Account Settings Windows, click “Data Files” tab and double click on a PST file
  • Click on “compact now” button to reduce the PST file size


It is always essential to compact PST files after you remove duplicate records from your Outlook account. However, removing Outlook duplicates from multiple Outlook mailboxes with manual process is not feasible as it will take considerable time of the user. Moreover, there is utmost chance that some matching records of Outlook mailboxes will be left undeleted by the user. Manual removal of Outlook duplicates will fail if PST files of Outlook mailbox have become oversized or damaged. So it is better to first split oversized PST file with a free Microsoft utility i.e. PST2gb.exe and then remove duplicate emails, contacts and other items from your Outlook mailbox.


Third party software such as Kernel for Outlook duplicates is most appropriate way of removing matching records from large as well as multiple outlook mailboxes. This Outlook duplicate email remover erase matching emails, contacts or other data based on different criteria. It also enable user to flag, permanently delete, copy or move the duplicate items of the Outlook mailbox. Outlook Duplicate email remover is compatible with MS Outlook 97, 98, 2002, 2003, 2007, 2010, 2013 and 2016 versions. It is also available free of cost to the users for limited period.