Corbett

Email Viewer Software

Corbett Email Viewer Software opens PST, OST, MBOX, EML, MSG, OLM, DBX and Google Takeout files or a live IMAP mailbox and shows every message with its attachments and headers. No Outlook, no Thunderbird, no account to create. Reading is free with no file or time limit. Windows only.

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4.6 out of 5 from 683 reviews

Files are opened read only on your own machine. Nothing is changed and nothing is uploaded.

Free to read, verified clean by VirusTotal and 30 days to claim your money back if you buy the export licence.

Reading and searching free Export licence $99 lifetime

Guide
Screens
Video

File coverage

Email Files the Viewer Opens

An email viewer is a read only program that opens a mailbox file without the client that wrote it. Corbett Email Viewer Software opens thirteen mailbox file types and Google Takeout archives, grouped below by the program that wrote them. It works out the format from the file itself, not from its extension.

Outlook

Other clients

MBOX
EML
EMLX
DBX
Maildir

Servers and archives

Google Takeout
Zimbra TGZ
CommuniGate
vCard

Live mailboxes

Gmail
Microsoft 365
Yahoo
iCloud
Any IMAP host

The file came from a program you do not have

That is the usual reason for an email viewer. An OST from a laptop that was wiped, an OLM from a Mac, a PST from a colleague who left. None of them need their original program installed to be read here.

Open MSG without Outlook

Core features

How the Email Viewer Works

Four screens, in the order a file is opened and read.

Open

Open a File, a Folder or a Profile

Browse to one file or point the email viewer at a whole folder and every supported file inside is loaded together. Pick a desktop client and its configured profile is found for you, so an old Outlook or Thunderbird install can be read without opening it.

One file, a folder of files or several at once
Configured profiles detected for ten desktop clients
Google Takeout ZIP opened without unpacking it first
Sign in to a live mailbox and read it in place instead

Browse

Browse the Mailbox as a Folder Tree

The file opens the way it looked in its original client. Inbox, Sent, subfolders and custom folders sit in a tree with a message count against each, so the size of what you are dealing with is clear before you read a line.

Folder hierarchy shown exactly as stored
Message count beside every folder
Empty folders hidden with one switch
Several files open side by side in one tree

Read

Read Mail in Four Views

Click a message and it opens in the preview pane with its attachments listed. Beside the normal reading view sit three analysis views. Investigators and IT staff use them to check where a message really came from before they act on it.

Content shows body, sender, recipient, subject and attachments
Contacts, calendar entries, tasks and notes listed where the file holds them
Message header exposes routing and delivery hops
Properties lists size, priority and flags
Hex and raw message give the full source

Search Inside the Email Files

Quick search takes a word and finds it anywhere. Advanced search narrows by field. Both work across every file you have open, so one sender across five archives is one search, not five.

Keyword search across body and subject
From, To, CC, BCC, subject and date range fields
Messages with an attachment only
Results kept while you open the next file

Before you start

Free Email Viewer, Paid Export

One download does five things. Reading, which you have just seen, is the free one. The other four write a new file or fill a new mailbox and those need a licence.

Covered here

Open and read

Load a file or sign in to a mailbox, browse the folders, read the mail, open the attachments, search. Free, with no limit on file count, file size or days.

Licence

File to file

Writing a PST as PDF or an MBOX as PST is the email converter tool. Same window, one more button.

Licence

Mailbox to file

Saving a live account to your disk is the email backup software.

Licence

Into a mailbox

A file into an account is the email recovery software. One account into another is the email migration tool.

The free edition writes 10 emails per folder, or 10 files, so you can check the output before paying. Reading has no such cap.

Typical reasons

Why Read Email Files Read Only

An email client imports the file and syncs it. An email viewer leaves it exactly as it arrived. Three situations where that difference matters.

Legal and HR

A file that must not change

Evidence, a complaint file, a mailbox handed over during a dispute. Importing it into Outlook rewrites dates and flags. The viewer reads it in place and the file on disk is not modified in any way.

IT and support

An old file with no program to open it

An OST left behind by a wiped laptop, a DBX from Outlook Express, an OLM from a Mac that was returned. The client that wrote them is gone. The viewer does not need it.

Everyday

Checking a backup actually opens

A PST or MBOX saved last year is only a backup if it opens today. Load it, read a few messages, open an attachment. If it needs converting to another format afterwards, the export button is in the same window.

Free

Open your file and read it now

Install it, load the file, read as much as you want. No sign-up and no licence needed for reading.

Download free viewer

Honest comparison

Email Client vs Email Viewer

Outlook opens PST, Thunderbird opens MBOX, Windows opens a single EML. If you already have the right client for your one file type, use it. The table shows where the viewer is the better choice.

Task	Outlook or Thunderbird	Email Viewer Software
Reply, forward and send	What a client is for	Read only, by design
Your one file type, already installed	Open it there	Also opens it
Cost	Classic Outlook needs a Microsoft 365 or Office licence	Free to read
Thirteen formats in one window	One or two each	PST, OST, MBOX, EML, MSG, OLM, DBX and more
Orphaned OST file	Outlook will not open it without the original profile	Opens it as a plain file
File left unchanged	Import makes a copy inside the client	Read in place, nothing written
Headers, hex and raw source	Headers only, inside a properties dialog	One click each, beside the message
Search across several archives	Each file imported first	Open them together, search once

Rows tinted green are the ones where the email client wins.

A single EML or MSG opens with a double click on most Windows machines. The viewer is for the folder of two thousand of them, or the file no installed program recognises.

Specifications

Email Viewer Requirements

Download details

Released: Dec 2020
Download size: 87.4 MB
Reading: Free, no limit
Export licence: $99 lifetime, up to 5 machines
Delivery: Download link and key by email

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System

Hard disk: 150 MB to install
RAM: 4 GB minimum
Processor: 1 GHz, 2.4 GHz advised
Rights: Run as Administrator
Mail client: Not required

Supported editions

Runs on Windows 11 through 7, either 32 or 64 bit. Server editions from 2025 back to 2008.

No macOS or Linux build.

Building Windows email utilities since 2020. The people who answer support tickets are the people who write the code.

Working process

Watch the Viewer Open a PST

Two minutes from download to reading a message. The same steps apply to every other file type.

Common questions

Email Viewer Software Questions

What is free, what the viewer opens and where it stops.

Is the email viewer really free?

Yes, for reading. Open any supported file or mailbox, browse every folder, read every message, open every attachment and search across all of it, with no file limit and no expiry. Money changes hands only if you export mail to another format or into another mailbox, which is a separate licence.

Do I need Outlook installed to view a PST file?

No. The email viewer reads PST, OST and MSG on its own, so a machine with no Outlook can open them. The same is true of OLM from Outlook for Mac and DBX from Outlook Express.

Can the email viewer open an OST file without the original profile?

Yes. Outlook refuses an OST once the account it belonged to is gone. The viewer treats it as a plain file and shows the folders and messages inside. If you then need it as a PST, the OST converter in the same window does that.

Does the email viewer change the file?

No. The file is opened read only and nothing is written back to it. Its size, dates and contents are the same after reading as before. That is what makes the viewer suitable for evidence and for files you have been asked to look at but not touch.

Can I view email attachments?

Yes. Attachments are listed with each message. Open one and it launches in whatever program handles that file type on your machine. Attachments can also be saved out on their own, which is part of the export licence.

Which email file formats can the viewer open?

PST, OST, MSG, OFT, OLM, MBOX, EML, EMLX, DBX, Maildir, Zimbra TGZ, CommuniGate and vCard, plus Google Takeout archives without unzipping them. A live Gmail, Microsoft 365, Yahoo, iCloud or IMAP mailbox can be signed into and read as well.

Is there a file size limit in the email viewer?

No. A 40 GB PST opens the same way a 40 MB one does. Large files take longer to index the first time, then folder browsing and search are immediate.

Can I search across several email files at once?

Yes. Open a folder of files and they all sit in one tree. Quick search and advanced search run across everything that is open, so one sender across a year of monthly archives is one query.

Can I view a Gmail or Microsoft 365 mailbox without downloading it?

Yes. Sign in and the mailbox loads as a folder tree, read directly from the server. Gmail and Yahoo need an app password, Microsoft 365 signs in through Microsoft's own page. Saving that mailbox to disk afterwards is the email backup software, with pages for the Gmail backup tool, Outlook.com backup tool, Hotmail backup tool, Office 365 backup tool and Yahoo backup tool and the iCloud backup tool, Webmail backup tool, Google Workspace backup tool.

What does the email viewer's message header view show?

Every Received line, the sender's real address, message ID, date stamps from each server and any authentication results. It is the view used to check whether a message really came from where it claims.

Can the email viewer open a corrupt PST?

Only if the file structure is still readable. A file that Outlook rejects as damaged usually needs repairing first. Our guide to repair PST file without ScanPST covers the free routes, then the viewer opens the result.

Does the email viewer run on Mac or Linux?

No. Corbett Email Viewer Software is a Windows application only, from Windows 7 through Windows 11 and Windows Server 2008 through 2025. It does read OLM and MBOX files written on a Mac.

By file type

Free Email Viewers by Format

Each page below covers one file type, what is inside it and what the viewer shows for it.

Free viewer pages

Opening files without their client

When reading is not enough

Writing a file is the email converter software. Saving a live account is the email backup software. Loading a file into an account is the email recovery software. Moving one account into another is the email migration tool.

User testimonials

What Email Viewer Users Say

Across 683 reviews of the backup and restore wizard.

4.6 out of 5

Collected across 683 reviews from software directories and direct customer feedback. The three below are unedited.

Email viewer for many providers

Viewing emails from so many different email service providers was never so easy before this. Props to the people behind this email viewer application. I would suggest this email viewer software to everyone.

Mark Rubin

Quick way to view email files

This email viewer tool was the perfect solution for my needs. If you're looking for a quick solution to view your email files, don't go any further. I would say this email viewer application is the best one to go for.

Summer Matthews

Reads mail from many clients

I highly recommend this email viewer tool to anyone looking for a quick solution for email viewing. Apart from its simple UI, I really liked the software's ability to view emails from so many different email clients.

Richard Faulkner

Get started

Read the Email File You Were Sent

Download the viewer, open the file and read it. Free for reading. If you later need it as PST, PDF or in another mailbox, the export licence is $99 one time with 30 day money back.

Download free viewer Purchase now

87.4 MB · Windows 11 to 7 and Windows Server 2025 to 2008 · 30 day money back