What is an OST file?

OST file stands for Offline Storage Table, which is an offline copy of the Exchange mailbox. You can open OST file in offline mode, andmake changes in it.The changes made in the OST file will get automatically updated by synchronization when connected with Exchange Server.

Where is the OST file located? OST file can be found without opening Outlook/ Exchange by 2 ways..

01 Searching at default location

You will find the OST file at this default location- C:\Users\user\AppData\Local\Microsoft\Outlook Or C:\Documents and Settings\\Local Settings\Application Data\Microsoft\Outlook

02 With Search option in OST Viewer tool

In OST Viewer tool, Search option automatically extracts all the stored OST files from the specified drive at one go.

To perform this, enter the drive location and click Search in Source File Selection dialogue box. All the OST files are extracted at once, thus making the task of locating OST file convenient for users.

OST Viewer Tool What’s it for?

Opening OST mailbox items without Exchange profile/connection

Salient Features

There are various integral features associated with the software that functions deeply for effective preview of all kinds of OST files.

Access OST Files Without Exchange Server

Access OST Files Without Exchange Server OST Viewer tool allows access to Exchange Offline folders file (OST) without establishing a connection with MS Exchange Server. The tool scans the OST file and displays its entire content, including emails, calendar items, notes, contacts, etc.

Find and Open Emails

Find and Open Emails Use its integrated ‘Find’ option to access specific email items. In the selected mailbox folders, you filter the emails by From, To, Subject, Date Range, Attachments, etc. Thus, you can locate and preview specific emails.

Saves Email List in HTML

Saves Email List in HTML You can save the selected email from the OST files in HTML format. It will save the email body that you can access in an offline manner. You can also check the related attachment of each email along with its message body.

Opens All Kinds of OST Files

Opens All Kinds of OST Files OST Reader tool is capable of opening orphaned, inaccessible, or corrupt OST files. The software is well-prepared to open OST file without connecting to an Exchange profile

Search OST Files

Search OST Files The tool makes the finding OST files easier with the Search option. This option locates the OST file within the specified location. You need to enter the drive in which you know your OST file is located. The tool will automatically fetch it, and you can open OST file by clicking on it.

Open Multiple OST Files

Open Multiple OST Files You can open as many OST files as required. There is no restriction on the number of OST files to view. Use + button to add multiple OST files in the Source File Selection dialogue box. This feature saves the users’ time from adding individual OST files one-by-one.

Generates File Analysis Report

Generates File Analysis Report The free OST Viewer tool generates reports with information on all item kinds, including emails, contacts, email flow density according to sender or data, notes, etc. It aids in the analysis of OST file data. These analysis reports provide a great deal about the OST file whose preview you have checked.

High Software Compatibility

High Software Compatibility Kernel OST Viewer Free tool extends support for all versions of MS Exchange Server (2019, 2016, 2013, 2010, 2007, 2003, 2000, 5.5, and 5.0), MS Outlook (Office 365, 2021, 2019, 2016, 2013, 2010, 2007, 2003, 2002, 2000, 98, and 97).

FAQs - Kernel OST Viewer

Kernel OST Viewer is an easy-to-use software used to view inaccessible, damaged,or corrupted OST files in a few simple steps. Let’s check them out.
  1. Run the software and click on the Browse button to select a single or multiple OST file(s) and click on Next to proceed.
  2. The system will show you the Process Information; there you need to click on the Finish button.
  3. In the next step, you need to click on the files you want to view. Select them one by one to view the content.
  4. Note: You can also generate an analysis report. For this, you need to select the type of report you want to generate from the right corner of the screen.

You can configure an Office 365 account in Outlook using IMAP configuration. Then as the rest data is saved as a copy of mailboxes in an OST file, the configured Office 365 data is also copied into the local OST file.
OST file, is an offline copy of the mailbox available on the Exchange. To access OST file with the latest information, synchronize it with Exchange. When the mailbox is unavailable on Exchange Server permanently, then the OST file is termed as an orphaned OST file.
Yes. You can view the attachments in the OST emails. Here are the steps:
  1. Step1: Select the folder from the left pane
  2. Step2: From the right pane, select the email of the attachment you want to open
  3. Step3: In the email preview double-click on the attachment.
You can use the Search option in the OST Viewer tool to find and open OST file easily by providing the drive location.
Using the File Analysis Reports feature, you can have the overall information about the content of the OST file. Let us have a look at the reports available.
  • Total item types: Generates a graph between Total item types and item count.
  • Mail flow density by date: Generates a graph between Item count and date.
  • Mail flow density by senders: Generates graph between Item count and senders.
  • Interaction between users: Generates graph between Item count against Sender & Receiver pair.

How it Works?


Software Prerequisites & Recommendations

About Software

  • Version: 21.1
  • Release Date: Jan 2021
  • License Type: Free

Version Support

Windows 365, 11, 10, 8.1, 8, 7, Vista, XP, 2000, 98, NT, 95

System Requirements

  • Hard Disk

    50 MB of disk space

  • Memory

    64 MB RAM (128 MB Recommended)

  • Processor

    Intel® Pentium Processor compatible (x86, x64) or equivalent

Software Guides

What customers say about Kernel OST Viewer

rating5 (4.9 / 5) 536 Reviews
  • 5 Star
  • 4 Star
  • 3 Star
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  • 1 Star
An effective and secure way to open OST files.

This software provides a simple and straightforward way to access and view data stored in OST files, without the need for an Exchange Server connection. I used it without paying any cost. Thanks you!

Full StarFull StarFull StarFull StarFull Star
Alberta Erickson
Verified, collected by Kernel Data Recovery
Yesterday 6:18pm
A free tool to view and open damaged OST file.

It is an excellent tool for anyone who needs to view their OST files without Exchange connection. The software is incredibly versatile, and it can display all types of OST files with ease. I highly recommend it!

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Lesley Howard
Verified, collected by Kernel Data Recovery
March 28, 2023
It is an exceptional tool for viewing and accessing Outlook OST files.

The software is very fast and efficient, allowing me to open and view OST files quickly. This feature is incredibly useful when I need to access a file quickly. I would like to give it full marks. Thank you!

Full StarFull StarFull StarFull StarFull Star
Robyn Francis
Verified, collected by Kernel Data Recovery
March 27, 2023
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