OST to MBOX Converter

Convert OST files from Microsoft 365, Exchange, IMAP, or Outlook.com accounts to Thunderbird MBOX quickly and easily.

  • Preserve folder structure, read/unread status, and other mail formatting and flags
  • Support for the latest Mozilla Thunderbird version
  • No Need for Outlook Installation
Get started for free

Product Information

Product name
OST 2 MBOX
Release date
May 2024
Category
OST Converter
Platform
Windows
Installation
Technical Specs
Additional terms
App Privacy
EULA

What's New

Version 1.28
Portable and Installer versions

How to convert OST to MBOX?

The OST to MBOX Converter Tool allows you to migrate OST files to Thunderbird MBOX format without requiring a connection to Microsoft 365, Exchange, IMAP, or Outlook.com accounts. To convert OST to MBOX, follow these steps:

  1. Choose a File or Folder with Outlook Data Files (.pst and .ost)
  2. Select the destination path for the resulting MBOX files
  3. Optionally, customize additional settings:
    • Process subfolders
    • Create individual folders for each Outlook Data File
    • Replicate folder structure from source Outlook Data File
    • Skip empty folders
    • Save internet transport headers
    • Overwrite mode for existing files
  4. Click "Run" to convert OST files to MBOX format
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OST to MBOX Portable Version (.zip) - No installation required

Usage: pst2mbox-cli [command] [options]

Command: convert mbox
Description: Convert PST and OST files to MBOX format

Options:
  -f, --file        Required. Path to the file(s) to be converted, supporting wildcard characters (*?).
  -r, --recursive   Process subfolders recursively.
  -q, --query       Search query for filtering messages.
  -p, --path        Destination path for MBOX files.
  -v, --verbose     Display detailed processing information on your screen.
  --fullscan        Perform an extensive scan for damaged or corrupted Outlook files.
  --harddel         Find and export 'hard deleted' and 'orphaned' items.
  --harddel-only    Export only 'hard deleted' and 'orphaned' items.
  --atchm-only      Export only attached emails.
  --mkdir           Create an individual directory for each exported file.
  --srcfolders      Preserve the source folder structure.
  --empty           Include empty folders in the export.
  --headers         Save internet transport headers.
  --enc-type        (Default: original) Recode Content-Transfer-Encoding. Valid values: original, quoted_printable, _7bit, _8bit, base64
  --utf-8           Set Content-Type Charset to UTF-8.
  --mode            (Default: rename) Overwrite mode. Valid values: rename, overwrite, append

Converting OST to MBOX using PowerShell

OST to MBOX Converter offers command line options for exporting items from .ost files to MBOX format. To start the export, use the convert mbox command followed by various options.

One of the key features is the ability to apply a search query to filter messages based on specific criteria, utilizing search keywords and boolean search operators. This allows users to extract only the relevant items they need, saving time and effort.

  • Support different naming conventions and macros for exported files
  • Convert attached emails
  • No Outlook installation required

Features

Standalone & Installer versions

OST 2 MBOX can be used as a portable application or installed as a Windows application. Choose the option that best suits your workflow needs.

Microsoft Outlook Not Required

Converting OST files to MBOX format doesn’t require Microsoft Outlook. This feature enables users to easily handle their email archives without additional software.

Offline Conversion

The OST to Thunderbird Converter does not require Internet access or authentication from a Microsoft Exchange Server or Windows Domain Controller.

Batch Conversion of OST to MBOX

With our OST to MBOX Converter, you can convert multiple OST files to MBOX format at once. This feature saves time and effort, especially when dealing with a large number of files.

Convert orphaned OST Files

Easily recover and convert OST files when the associated Mail Profile is missing, corrupted, or replaced with a new one.

Convert damaged OST files

Convert OST files after unsuccessful recovery attempts using the ScanOST.exe tool, allowing you to restore emails, attachments, and other important items that may otherwise be lost.

Preserve All Mail Properties

The osttombox conversion program preserves all mail properties, including To, Cc, Bcc, From, Subject, and Date. It also maintains the read/unread status and other mail formatting and flags.

No Limits on the Number of Resulting Files

There are no limits on the number of resulting files and files to be converted. You can convert an unlimited number of folders or files as often as you want.

Converts Password-Protected OST Files

No need to worry if your OST files are password-protected—our converter can handle them. Easily convert these files without needing to enter the password.

Compatible with all Outlook versions

Convert OST files from Outlook 2021, 2019, 2016, 2013, 2010, and 2007, as well as from IMAP, Microsoft 365, Exchange, and Outlook.com accounts.

Frequently Asked Questions

Have questions about OST to MBOX Converter? Check out our answers to frequently asked questions below to get started!

Follow these steps to import .ost files into Thunderbird.
  1. Download OST to MBOX Converter
    Install the OST to MBOX Converter, then browse for your .ost files.
  2. Convert OST Files to MBOX Format
    Set your conversion options and click "Run." Wait for the export to complete.
  3. Find Your Thunderbird "Local Folders" Directory
    Open Thunderbird, right-click on "Local Folders," and select "Settings." Under "Account Settings," locate the "Local directory."
  4. Copy MBOX Files into Local Folders
    Close Thunderbird. Open the "Local Folders" directory in your file explorer, then drag and drop your MBOX files into it.
  5. Restart Thunderbird
    Relaunch Thunderbird, and you should see the imported Outlook mailboxes in your Local Folders list.

Note: The evaluation version exports up to 15 emails per folder.

An MBOX is a format used for storing email messages, and it is supported by common email clients. It contains all the details for the exported messages, including message text and any attachments. MBOX files typically result in the creation of:
  • The .sbd folders - used to store the folder hierarchy.
  • The files that actually contain your messages (do not have any three-letter extension at all): Archive, Calendar, Contacts, Inbox,..

Certainly, you can export the corrupted OST file to MBOX format without experiencing any data loss. The command line options also enable you to recover hard-deleted emails during the conversion process.

The MBOX format is standardized, but differences in newline characters and encoding between Windows and Linux may affect Thunderbird’s ability to recognize emails. To ensure proper compatibility, use the ImportExportTools NG extension in Thunderbird:

  1. Open Thunderbird on your Linux system.
  2. Install ImportExportTools NG:
    • Go to Menu ☰ → Add-ons and Themes
    • Search for ImportExportTools NG and install it.
  3. Restart Thunderbird.
  4. Right-click Local Folders → Select ImportExportTools NG → Import mbox Files.
  5. Choose All mbox Files from directory (with sbd structure), then browse to your converted file.

This method should allow Thunderbird to correctly recognize and display your emails.