How to Open PST Files Without Outlook (Windows, Mac, Linux)

Why You Might Need to Open PST Without Outlook

PST (Personal Storage Table) files are the standard archive format for Microsoft Outlook. They contain emails, contacts, calendar events, and other mailbox data in a single file. But there are plenty of situations where you need to access the contents of a PST file and Outlook is not available.

Perhaps you are on a Mac or Linux machine where Outlook is not installed. Maybe you received a PST file from a colleague but your organization uses a different email client. You might be a legal professional reviewing email archives for compliance or eDiscovery purposes and need a lightweight viewer rather than a full Outlook installation. Or you may simply prefer not to install Outlook just to read a few archived emails.

Whatever the reason, PST files are not locked to Outlook forever. Several methods exist to read, search, and extract data from PST files on any operating system without purchasing or installing Microsoft Outlook.

What Is Inside a PST File

Before exploring how to open a PST file, it helps to understand what it contains. A PST file is a structured binary database that can hold several types of data:

• Emails with full message bodies, headers, and attachments.
• Folder structure including Inbox, Sent Items, Drafts, Deleted Items, and custom folders.
• Contacts with names, email addresses, phone numbers, and other fields.
• Calendar events with dates, attendees, recurrence patterns, and reminders.
• Tasks and notes from Outlook’s task management and note-taking features.

The file format follows the Microsoft Open Specification (MS-PST), which defines a layered architecture with node databases, B-trees, property contexts, and table contexts. PST files can range from a few megabytes to over 50 GB depending on how much data they contain.

For a comprehensive overview of the format, see What Is a PST File.

Option 1: Preview PST Online With MailtoPst

The fastest way to look inside a PST file without installing anything is to use an online viewer. MailtoPst lets you upload a PST file directly in your browser and browse its contents.

How It Works

1. Go to mailtopst.com and upload your PST file.
2. The service parses the PST structure server-side and presents the folder hierarchy.
3. Browse folders, read individual emails, and view attachment lists.
4. If needed, convert the PST to another format for use in your preferred email client.

This method requires no software installation, works on any operating system with a modern browser, and handles the complex binary parsing of the PST format entirely on the server. It is ideal for quick access when you need to find specific emails or verify the contents of a PST archive.

MailtoPst provides 100 MB free credit, which is enough to preview a small to medium-sized PST file or test the conversion process with a sample of your data.

Option 2: Convert PST to a Universal Format

If you need ongoing access to the emails inside a PST file, converting it to a more widely supported format is often the best approach. Two formats stand out as practical alternatives.

Convert PST to MBOX

MBOX is an open format supported by Thunderbird, Apple Mail, and most Unix-based email systems. Converting your PST to MBOX lets you open the emails in any of these clients without Outlook.

Use the PST to MBOX converter to upload your PST file and download the resulting MBOX. You can then import the MBOX into Thunderbird using the ImportExportTools NG add-on, or into Apple Mail using File > Import Mailboxes. The conversion preserves your folder structure, message metadata, and attachments.

This is the recommended path if you plan to use Thunderbird or Apple Mail as your primary email client going forward. For a detailed guide on the reverse operation, see How to Convert PST to MBOX Without Outlook.

Convert PST to EML

EML is the most universally compatible email format. Each message becomes an individual .eml file that can be opened by virtually any email client, including Thunderbird, Apple Mail, Windows Mail, and even Outlook itself.

Use the PST to EML converter to extract individual messages from your PST file. This approach is particularly useful when you need to share specific emails with others, attach them to support tickets, or integrate them into document management systems.

EML files are plain-text based and can even be opened in a text editor if needed, making them the most accessible format for individual message viewing.

Opening PST Files on Windows Without Outlook

Windows users have several options beyond Outlook for accessing PST files.

SysTools PST Viewer

SysTools offers a free PST viewer for Windows that can open and display PST file contents without requiring Outlook. It renders emails with formatting, shows folder structure, and lets you view attachments. The free version is read-only, which is sufficient for browsing archived emails.

Kernel PST Viewer

Another free Windows tool that opens PST files independently of Outlook. It displays emails in a familiar three-pane layout with folder tree, message list, and reading pane. The viewer supports both ANSI and Unicode PST files.

Thunderbird via Conversion

If you already use Thunderbird on Windows, convert your PST to MBOX using MailtoPst and import the result into Thunderbird. This gives you full read and write access to the emails within a capable email client, along with search and filtering capabilities.

Command-Line Tools

For technical users, the open-source readpst utility (part of the libpst package) can extract emails from PST files directly from the command line. While libpst is primarily a Linux tool, Windows users can run it through WSL (Windows Subsystem for Linux):

sudo apt install pst-utils
readpst -o output_folder/ your_file.pst

This extracts all emails from the PST file into MBOX or individual files in the specified output directory.

Opening PST Files on Mac

macOS does not include any native support for PST files. Outlook for Mac can open PST files, but if you do not have Outlook installed, here are the alternatives.

Online Conversion

The simplest approach for Mac users is to upload the PST file to MailtoPst and convert it to MBOX format. You can then import the resulting MBOX file directly into Apple Mail using File > Import Mailboxes > Files in mbox format. The entire workflow requires only a browser and Apple Mail, both of which come pre-installed on every Mac.

For a dedicated guide, see How to Open a PST File on Mac.

Thunderbird

Install Thunderbird for macOS and use the conversion-then-import approach described above. Thunderbird provides a full-featured email client that handles MBOX natively, making it a solid permanent solution if you frequently work with email archives.

readpst on macOS

The readpst command-line tool can be installed on macOS through Homebrew:

brew install libpst
readpst -o output_folder/ your_file.pst

This extracts the PST contents into MBOX files organized by folder. It runs locally on your machine and does not require uploading data to any service, which may be important for sensitive archives.

Opening PST Files on Linux

Linux users benefit from strong command-line support for PST files, along with graphical options.

readpst (libpst)

The readpst utility is the standard Linux tool for extracting PST file contents. Install it through your distribution’s package manager:

# Debian/Ubuntu
sudo apt install pst-utils

# Fedora/RHEL
sudo dnf install libpst

# Arch Linux
sudo pacman -S libpst

Basic extraction to MBOX files:

readpst -o output_folder/ your_file.pst

Extract to individual EML files instead:

readpst -e -o output_folder/ your_file.pst

Preserve folder structure:

readpst -r -o output_folder/ your_file.pst

The -r flag creates subdirectories matching the PST folder hierarchy. The -e flag extracts each message as a separate file. These can be combined for maximum flexibility.

Thunderbird

Thunderbird works on Linux and provides a graphical alternative. Convert the PST to MBOX using either readpst locally or MailtoPst online, then import the MBOX files into Thunderbird.

Evolution

GNOME’s Evolution email client can import PST files through the evolution-pst-import plugin. Once installed, go to File > Import and select your PST file. Evolution will parse the file and add the contents to your local mail.

For Legal and Compliance Teams

PST files frequently appear in legal discovery, regulatory compliance, and internal investigations. Legal teams and compliance officers often need to review large volumes of archived emails without deploying Outlook to every reviewer.

eDiscovery Workflows

In eDiscovery scenarios, PST files may need to be processed by specialized review platforms. Converting PST to EML using the PST to EML converter produces individual message files that can be loaded into most eDiscovery platforms, including Relativity, Nuix, and Concordance. Each EML file retains its metadata, making it suitable for chronological sorting, keyword search, and deduplication.

For more on email review in legal contexts, see our eDiscovery use case.

Compliance Archiving

Organizations subject to regulatory retention requirements may receive PST files from departing employees. Converting these to MBOX or EML ensures long-term accessibility regardless of future email software choices. MailtoPst processes files on EU-hosted servers and does not retain uploaded data after conversion.

Access Your PST Files Now

You do not need Microsoft Outlook to read PST files. Whether you are on Windows, Mac, or Linux, there are practical methods to access your email archives. For the quickest path with no installation, upload your PST to MailtoPst and either preview the contents online or convert to MBOX or EML format for use in your preferred email client.

You get 100 MB free credit to try it with your own PST file. Upload, browse, and convert entirely in your browser.

Convert now