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.pst
Email & CommLow Risk
62/100 Popularity

.PST File Extension Reference

The .PST and .OST formats are the Microsoft Outlook personal and offline folder files, identified by the !BDN magic bytes. Files with the .PST extension are categorized under Email & Comm and are widely utilized in modern computing environments for storing, rendering, and exchanging structured data. By verifying the header signature (21 42 44 4E) using forensic byte inspection tools, users can authenticate file integrity and rule out disguised executable payloads.

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Quick Specification & Metadata

.PST
File Extension

.PST

Category

Email & Comm

MIME Type

application/vnd.ms-outlook

Developer / Owner

Microsoft Corporation

First Released

N/A

Licensing Standard

Proprietary / Patent Licensed

Format Structure

Binary Header Data

Typical File Size

100 MB - 50 GB

Common Usage:pst file, open pst, outlook pst file

Online .PST Viewer & Live Inspector

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Client-Side Memory

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What is a .PST File? (Technical Definition & Architecture)

ISO / IETF / Industry Standard

The .PST and .OST formats are the Microsoft Outlook personal and offline folder files, identified by the !BDN magic bytes. Files with the .PST extension are categorized under Email & Comm and are widely utilized in modern computing environments for storing, rendering, and exchanging structured data. By verifying the header signature (21 42 44 4E) using forensic byte inspection tools, users can authenticate file integrity and rule out disguised executable payloads.

Binary Encoding
Structured Data Stream

Formatted byte alignment adhering to international format specifications.

Validation Standard
Specification Conformance

Adheres to formal schema and protocol documentation.

Cross-Platform Portability
Cross-Platform Interoperability

Parsed and executed identically across Windows, macOS, and Linux kernels.

PST Binary Structure & Header Specifications

The .PST format organizes data into validated sequential or hierarchical byte structures. Inspecting the header offset reveals the magic byte sequence 21 42 44 4E.

  • File Signature (Magic Bytes): 21 42 44 4E
  • MIME Content-Type: application/vnd.ms-outlook
  • Payload Structure: Optimized data stream with metadata headers and checksum records.
  • Safety Classification: Low Risk – PST archives can contain malicious email attachments Repair oversized or corrupt PST files with the Inbox Repair Tool (scanpst) Files ending in .PST should always be inspected for valid magic bytes to verify they match legitimate Email & Comm specifications.

How to Open .PST Files on Windows, Mac & Android

Step-by-Step OS Guide
How to Open on Windows 10/11
  1. 1Primary Application: Double-click or open directly with Microsoft Outlook.
  2. 2Alternative Software: Open using SysTools PST Viewer.
  3. 3File Association: Right-click the file, select Open with > Choose another app, and check Always use this app.
How to Open on Mac & iPhone
  1. 1Native macOS Application: Open with Microsoft Outlook.
  2. 2Quick Look Preview: Highlight the file in Finder and tap the Spacebar.
  3. 3Set Default App: Press Cmd + I, expand Open with, select your application, and click Change All.
How to Open on Android & Mobile
  1. 1Compatible Mobile Apps: Download a dedicated viewer for .pst from the Google Play Store.
  2. 2Cloud Storage: Open through Google Drive, Dropbox, or OneDrive mobile apps.
  3. 3Online Browser Conversion: Use AnyFileX mobile browser tools to convert the file into universal PDF or image formats.

Convert .PST Files Online & Free

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.PST to .PDFTop ConversionFast Online

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.PST to .JPGUniversal ExportStandard Output

Export .PST files to .JPG for universal cross-platform viewing, printing, and sharing.

.PST MIME Types & HTTP Server Headers

IANA Standard

When serving .pst files over HTTP or configuring REST APIs, web servers must send the official IANA registered Content-Type headers:

MIME Type IdentifierStandard UsageFile ExtensionsCopy
application/vnd.ms-outlookStandard official MIME type for .pst files.pst
Nginx / Apache Server Configuration
# Nginx mime.types
types {
    application/vnd.ms-outlook             pst;
}

# Apache .htaccess
AddType application/vnd.ms-outlook .pst

.PST Magic Bytes & Hex File Signatures

Offset 0x00

In digital forensics and file signature analysis, authentic .pst files begin with a standardized magic byte sequence at byte offset 0x00 to verify file integrity and prevent extension spoofing:

Standard Hex Header Signature
Hex Representation:21 42 44 4E
ASCII Representation:PST
Byte OffsetOffset 0x00
Leading Hex Signature21 42 44 4E
ASCII RepresentationPST
Forensic DomainEmail & Comm File Format

.PST vs .PDF (Detailed Format Comparison)

Head-to-Head
Feature Metric.PST.PDFAdvantage
Format Full NamePST File FormatPortable Document FormatTie / Equal
CategoryEmail & CommDocumentsTie / Equal
MIME Content-Typeapplication/vnd.ms-outlookapplication/pdfTie / Equal
Binary Header (Magic Bytes)21 42 44 4E25 50 44 46 2D (%PDF-)Tie / Equal
Typical Storage Footprint100 MB - 50 GB200 KB – 25 MBTie / Equal
Universal Native SupportRequires SoftwareHigh / OS StandardTie / Equal

.PST Compatibility Matrix

Windows 11 / 10

Supported natively or through Microsoft Outlook

Full Support
macOS Sonoma / Ventura

Supported natively or via SysTools PST Viewer

Supported
Linux (Ubuntu / Fedora)

Supported via open-source tools and command line utilities

Supported
iOS & iPadOS

Accessible through compatible mobile viewers or cloud previewers

Mobile App
Android 10+

Supported through dedicated mobile apps or cloud viewers

Mobile App
ChromeOS

Accessible via web browser applications and Chrome extensions

Web / App

Recommended Software for .PST

2 Verified Apps
M

Microsoft Outlook

Microsoft Corporation

Paid / Commercial
4.7 / 5.0
•
Compatible with .PST
S

SysTools PST Viewer

Microsoft Corporation

Paid / Commercial
4.8 / 5.0
•
Compatible with .PST

Common Errors & Troubleshooting .PST Files

Troubleshooting
1Inspect File Header: Use the AnyFileX Magic Byte Detector to verify that the first bytes match 21 42 44 4E.
2Prevent Extension Spoofing: Ensure "File name extensions" is checked in your OS file manager to detect disguised double extensions (e.g., file.PST.exe).
3Verify Checksum Integrity: Calculate SHA-256 or MD5 hashes against source downloads using our online Checksum Verifier.
4Inspect Container Structure: If PST files fail to launch, verify whether the file was truncated during download or corrupted in transit.

Security & Malware Risk Assessment

Low Risk

Can a .PST file carry viruses or malware?

PST archives can contain malicious email attachments Repair oversized or corrupt PST files with the Inbox Repair Tool (scanpst) Files ending in .PST should always be inspected for valid magic bytes to verify they match legitimate Email & Comm specifications.

Executable Macros

No active macro execution support

Sandboxed Parsing

Safe to inspect with AnyFileX's browser sandbox

Safety Checklist Before Opening
  • •Verify file extension in OS File Explorer options ('Show known file extensions').
  • •Verify magic bytes (21 42 44 4E) to ensure the file isn't a renamed executable.
  • •Do not open .PST attachments received unexpectedly via email or instant messenger.

Preguntas frecuentes

Respuestas claras a las preguntas más habituales.

A .PST file is a PST File Format associated with Email & Comm. PST (Personal Storage Table) is the local data file for Microsoft Outlook, holding emails, contacts, and calendar items. It begins with the !BDN signature and can grow to tens of gigabytes.
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    A .PST file is a PST File Format file format categorized under Email & Comm. PST (Personal Storage Table) is the local data file for Microsoft Outlook, holding emails, contacts, and calendar items. It begins with the !BDN signature and can grow to tens of gigabytes.

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