Outlook Duplicate Remover Outlook Duplicate Remover
4.5 · 1145 votes

Download Outlook PST Duplicate Remover Software

Outlook Duplicate Remover clears duplicate emails out of Outlook PST and OST files without touching the original. The unique messages go to a fresh PST you choose.

   
 Download for Free
Windows 11 / 10Free trial, no sign-up
Outlook Duplicate Remover Screenshot.
Duplicate emails come from IMAP accounts, a mailbox synced on two computers, or a PST you imported twice. Outlook's own Clean Up checks one folder at a time, missing copies in Sent and Archive. Outlook Duplicate Remover reads the PST or OST directly on your PC, with no Outlook running. It groups duplicates by your rules and writes a fresh PST with one copy of every message, leaving the source untouched, whether you are on Windows 11 or cleaning an old export from Outlook 365.

How to download and use Outlook PST Duplicate Remover Software

Open your PST or OST.
1

Open your PST or OST

Point the Outlook PST Duplicate Remover Software at any Outlook data file. The folder tree loads with checkboxes, and each message shows its subject, sender and date, alongside its size.

Choose folders and match rules.
2

Choose folders and match rules

Tick the folders to scan and choose what makes two emails a duplicate: Subject, sender, body text, and more. Cross-folder scanning is on, comparing Inbox and Sent together.

Pick which copy to keep.
3

Pick which copy to keep

Keep the first, oldest, or newest message in each group, and set the output folder for the cleaned PST. Turn on the backup file if you want a rollback.

Run and check the report.
4

Run and check the report

Run the job to create a new PST with only the unique emails and a CSV log of every group kept or removed. Open the report in Excel.

Your original mailbox is never touched.

Your original mailbox is never touched

We leave your source file unchanged, byte for byte, and write the unique messages to a separate new PST. If your match rules group the wrong messages together, you can run again with stricter rules. Your original mailbox is safe.

   
 Download for Free

Catches the duplicates Clean Up leaves behind

Outlook's Clean Up command removes copies within a single conversation or folder. Copies also appear across Inbox and Archive, when a whole account is imported on top of another, or when threads multiply after a repair. One bad re-sync on a busy IMAP mailbox has pushed a 22,000-message folder past 33,000. The program compares messages across every folder you check.

   
 Download for Free

Catches the duplicates Clean Up leaves behind.
Everything runs on your own PC.

Everything runs on your own PC

Your clean copy is saved beside the original, with no upload, web service or cloud account. For regulated inboxes in law or finance, processing on your own computer is a requirement. We make it the default.

   
 Download for Free

Match on the fields you choose

Six fields define a duplicate: Subject, sender, message body, recipients, date, and attachment names. Tick the ones that matter. The body is compared as a normalized hash, and RE: and FW: prefixes can be ignored so replies still line up.

You pick which copy survives

By default, you keep the first copy found in each group. One click switches to the oldest or newest, letting you keep the tidier, better-filed copy of a thread.

Reads PST and OST directly

Both Outlook file types open the same way, with no Outlook profile or Exchange setup to configure. Browse the full tree, expand every level, and select only what you want scanned.

Filter before you clean

Preview part of your mailbox before a full run: narrow the message list with a text filter across the Subject, From, To, and body fields, and apply it.

A CSV report of every change

Each group is logged with its folder, Subject, sender, date, and whether the copy was kept or removed. The file is plain RFC4180 CSV with a UTF-8 marker, so it opens cleanly in Excel.

Optional backup of what was removed

Switch on the backup and the removed duplicates are saved to a second PST of their own. If you ever want them back, they are one import away.

Outlook Duplicate Remover
Outlook Duplicate RemoverOutlook PST Duplicate Remover Software cleans a whole PST in one pass. The original file stays exactly as it was.
 Download

Who uses Outlook Duplicate Remover Software?

IT admins and migrators

Clean mailboxes after a PST import or an Exchange move, when messages land twice and users complain about clutter.

Long-time Outlook users

Clear unwanted copies from your personal archive after years of mail across a couple of email accounts have left it heavy and slow to open.

Support and handover teams

Slim down an inherited mailbox before passing it on, such as an ex-colleague's 6 GB archive with three dozen subfolders.

Outlook Duplicate Remover
Outlook Duplicate Remover
Price
from $ 29.99
Version
1.7
File Size
8 Mb
Last updated on
02/09/26
System Requirements
  • Windows 11/10/8.1/8/7 (32/64 bit)
  • Intel i3, AMD Ryzen 5 or above
  • 4 GB of RAM or above
  • NVIDIA® GeForce® series 8 and 8M, Intel® HD Graphics 2000, Quadro FX 4800, Quadro FX 5600, AMD Radeon™ R600, Mobility Radeon™ HD 4330, Mobility FirePro™ series, Radeon™ R5 M230 or higher graphics card with up-to-date drivers
  • 1280 × 768 screen resolution, 32-bit color
  • 1 GB of free hard disk space or above

Frequently Asked Questions

An IMAP account or importing the same PST twice is usually the cause. Syncing one mailbox on two machines can do it too, as can a rule that copies mail into a second folder or a repair that re-downloads messages you already had.

No. Clean Up clears redundant replies within a single conversation or folder. Outlook Duplicate Remover also catches the same email in two different folders or brought in by a second account.

Open your PST or OST directly in the program, without Outlook, a mail profile or an Exchange account. Select the folders and match rules, and choose where to save your de-duplicated copy.

You can find free scripts and VBA macros online, but most delete messages from your live mailbox, risking mail you wanted to keep if the match is wrong. Our trial lets you run on a sample and inspect a clean copy before committing to the whole file.

No, never. The source PST or OST is only ever read, not written to. Every removal happens in a brand new file, and you can also keep a separate backup PST of the messages that were taken out, so nothing is truly gone.

Yes. Tick as many folders as you like. The program compares all of them at once, catching copies in Inbox, Sent, and Archive.

The first copy found is kept by default. You can choose the oldest or newest in each group instead. Your chosen message goes into the clean PST as the original; the remaining copies are set aside.

Rate Outlook Duplicate Remover

  • Windows 7
  • Windows 8
  • Windows 10
  • Windows 11
Author: SoftOrbits (English)
4.5
Avg. rating: 4.5 from 1145 votes
Good
 Download for Free

Risk-free download

progressive-webapps/apis/offline-first Created with Sketch.
100% offline
Your files never leave your PC
Safe & secure download
Directly from the official website
No sign-up required
No account or email to get started
Trusted since 2006
Desktop software for Windows