Development

PST Inspector

Outlook File Viewer – A Lightweight, Standalone PST/OST Explorer

PST Inspector – View Outlook PST/OST files without Outlook installation. Browse, print & export emails. Free Outlook PST Viewer.

Need to view the contents of a PST or OST file, but don’t have Outlook installed?
PST Inspector is a free, standalone tool that lets you open and explore Outlook data files — no Outlook, no Office, no MAPI required.

Lightweight and easy to use, PST Inspector gives you full access to folder structures, messages, attachments, and more — including legacy and modern file formats.

PST Inspector is designed for IT professionals and advanced users who need to access, print, and export Outlook PST/OST files without installing Microsoft Outlook.

Why Choose PST Inspector?

PST Inspector is a lightweight, free Outlook file viewer designed for users who need seamless access to PST and OST files — without having Microsoft Outlook, Office, or MAPI installed. The tool stands out for its simplicity, portability, and its ability to expose deep insights into email data and folder structure.

Key Features and Strengths

Standalone operation: No Outlook or Office required. PST Inspector opens PST and OST files directly, enabling users to examine mailbox contents effortlessly.
Detailed inspection: Navigate the full folder hierarchy, inspect detailed properties of messages, attachments, folders, and recipients, and even view binary data blocks.
Broad format support: Compatible with both legacy ANSI formats (Office 95/97/2000) and modern Unicode PST files.
Export and print capabilities: Beginning with version v0.9.9.5, users can print emails directly. Later updates added the ability to export messages as standalone .msg files (v0.9.9.8) and .eml files (v0.9.9.9).
Totally free: No trials, no limitations — PST Inspector remains fully functional and free to use indefinitely.
Actively developed: The tool is under active development, with future enhancements driven by user feedback and suggestions.

Ideal For

PST Inspector is ideal for IT professionals, data recovery experts, forensic analysts, and advanced users who require a reliable, no-cost solution to view, export, or print Outlook data files without needing Outlook installed.

Overall Impression

With its clean interface, zero-dependency design, and essential export features, PST Inspector is a powerful yet accessible tool for advanced users and IT professionals. Whether you’re troubleshooting corrupted archives, exploring email contents, or conducting forensic analysis, PST Inspector delivers dependable functionality without bloat. Its continuous updates and openness to user suggestions further reinforce its value to technically inclined users.

Outlook PST Viewer Key Features:

View Outlook PST and OST files without Outlook or Office
No MAPI dependency required
Browse and navigate the full folder structure of the file
Inspect binary data blocks within the file
View detailed properties of folders, messages, attachments, and recipients
Supports both ANSI and UNICODE PST files – including legacy formats from Office 95/97/2000, as well as the latest MS Office versions
100% free to use

Who Can Benefit Outlook PST Viewer

PST Inspector is built for advanced users and IT professionals who need reliable access to Outlook data files without installing Microsoft Outlook.

IT administrators and support engineers – quickly troubleshoot mailboxes, recover data, and export messages for further use.
Forensics and security specialists – examine email content, attachments, and hidden properties during digital investigations.
Data recovery experts – extract critical information from damaged or orphaned PST/OST files.
Power users – browse, print, and export emails to .msg or .eml formats with full control, without relying on Outlook.
System integrators and developers – analyze MAPI properties and test interoperability with custom tools and workflows.

The product is currently under active development. Future updates and enhancements will depend on user interest and feedback.

If you’d like more information or wish to suggest new features, feel free to contact us at: info@imibo.com

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PST Viewer Version History

v0.9.9.1
Initial public release featuring basic PST/OST viewing functionality.

v0.9.9.2
Introduced the ability to view detailed item properties within PST files.

v0.9.9.3
Added support for navigating system folders such as Inbox, Sent Items, Calendar, and others.

v0.9.9.5
Enabled printing of email messages directly from the viewer.

v0.9.9.8
Implemented the option to save emails as standalone Outlook .msg files
(using the Unicode format compatible with Microsoft Outlook 2003 and later).

v0.9.9.9
Implemented the option to save emails as standalone MIME *.eml files

v0.9.9.10
Added ability to search messages by sender, recipient, subject, date
Added calculated Store properties

v0.9.9.11
Added calculated Message properties
Added calculated Attach properties
Added calculated Folder properties
Added ability to sort messages by Recipient, Sender, Subject, Date
Cosmetic UI changes

v0.9.9.12
Added detailed view for Contact item
Added contact export to RFC vCard

v0.9.9.13
Improved vCard export

v0.9.9.14
Improved StickyNote processing and visualization
Added StickyNote color processing depending on their categorization
Improved RTF body extraction and visualization

v0.9.9.15
Improved iCalendar export

v0.9.9.16
Improved column view of the Task object
Improved detailed preview of the Task object
Added search in Named properties MAP

Key Benefits

✅ No Outlook or MAPI required
✅ No installation needed
✅ Completely free – no trial periods, no limitations

Simply open your PST or OST file with PSTInspector to view, print, or export your emails with ease.
A fully functional, permanently free application.

vCard export

Supported vCard Versions

vCard 2.1 (1996) – with Quoted-Printable encoding
vCard 3.0 (1998) – with backslash escaping
vCard 4.0 (2011) – with data URI scheme

Supported Properties

Identification

N – Structured name (Last, First, Middle, Prefix, Suffix)
FN – Formatted name
NICKNAME – Nickname or alias
UID – Unique identifier (auto-generated GUID)

Contact Information

TEL – Phone numbers with 9 types (Voice, Cell, Fax, Video, Text, Pager, Textphone, Car, ISDN) and locations (Home, Work, Other)
EMAIL – Email addresses with location types and preference support
URL – Web addresses (Work/Home)
IMPP – Instant messaging (Skype, XMPP, Telegram, WhatsApp, Signal, Viber, and 6 more protocols)

Addresses

ADR – Structured postal addresses with multiple entries
LABEL – Formatted address labels (vCard 2.1 & 3.0 only)
Address types: Home, Work, Other with preference support

Organization

ORG – Organization name and organizational unit
TITLE – Job title
ROLE – Role or occupation

Personal Information

BDAY – Birthday (ISO 8601 format)
ANNIVERSARY – Anniversary date
GENDER – Gender (with X-GENDER for older versions)

Classification & Organization

CLASS – Access classification (Public, Private, Confidential)
CATEGORIES – Multiple category tags
SORT-STRING – Custom sort string (vCard 2.1/3.0) or SORT-AS parameter (vCard 4.0)

Relationships (Microsoft Outlook Compatible)

Spouse – Spouse/partner name (X-MS-SPOUSE)
Children – Multiple children names (X-MS-CHILD, X-CHILD)
Manager – Manager name (X-MS-MANAGER, X-MANAGER)
Assistant – Assistant name (X-MS-ASSISTANT, X-ASSISTANT)

Multimedia

PHOTO – Inline Base64 encoded images (JPEG, PNG, GIF, BMP)
KEY – X.509 certificate for encryption

Additional

NOTE – Free-form notes with multi-line support

RFC Compliance

Primary Standards

RFC 2425 – MIME Content-Type for Directory Information
RFC 2426 – vCard MIME Directory Profile (vCard 3.0)
RFC 6350 – vCard Format Specification (vCard 4.0)

Supporting Standards

RFC 2045 – Quoted-Printable Content-Transfer-Encoding
RFC 2397 – Data URI scheme
RFC 2425 – Line folding (75-76 characters)

Microsoft Compatibility

MS-OXVCARD – Microsoft Exchange Server vCard extensions

Key Features

Encoding & Character Support

UTF-8 encoding for all versions
Quoted-Printable encoding for vCard 2.1 (non-ASCII characters)
Backslash escaping for vCard 3.0/4.0 (special characters: ,, ;, \, \n)
Line folding at 75-76 characters per RFC requirements
Full Cyrillic and international character support

Advanced Functionality

Multiple entries support (phones, emails, addresses, URLs, instant messaging)
Preference marking (PREF parameter)
Type categorization (Home, Work, Other)
Base64 encoding helper for binary data
IMPP protocol detection from full addresses (e.g., “skype:username”)
Automatic UID generation using GUID

Data URI Support (vCard 4.0)

Inline photos using data:image/jpeg;base64,
X.509 certificates using data:application/x-x509-ca-cert;base64,

Design Principles

RFC-compliant implementation
Version-specific formatting (respects differences between 2.1, 3.0, and 4.0)
Microsoft Outlook compatibility through X-extensions
Comprehensive error handling
Memory-efficient dynamic arrays
Clean API with intuitive method names

This implementation provides enterprise-grade vCard generation suitable for contact management systems, CRM applications, email clients, and any software requiring standards-compliant electronic business card functionality.

iCalendar Export for Appointments

Professional RFC 5545 compliant conversion from PST to iCalendar format

Standards Compliance

RFC 5545 100%

Full iCalendar 2.0 specification compliance

RFC 2445 Compatible

Backward compatible with older implementations

MS-OXOCAL Supported

Microsoft Outlook Calendar Object Protocol

Exported Properties

Core Event Information

UID – Unique event identifier (optimized format)
DTSTAMP – Creation/modification timestamp
DTSTART / DTEND – Start and end times with timezone support
SUMMARY – Event title with full UTF-8 support
DESCRIPTION – Plain text event description
LOCATION – Meeting location or resource
X-ALT-DESC – Rich HTML description (optional)

Participants & Organization

ORGANIZER – Event organizer with contact information
ATTENDEE – All attendees with roles (Required, Optional, Resource) and response status
Smart duplicate detection – eliminates repeated attendee entries
Support for Chair, Required Participant, Optional Participant, and Non-Participant roles

Scheduling & Status

STATUS – Confirmed, Tentative, Cancelled
TRANSP – Free/Busy status (Opaque, Transparent)
PRIORITY – High, Normal, Low priority levels
CLASS – Public, Private, Confidential visibility
SEQUENCE – Version tracking for updates
CREATED / LAST-MODIFIED – Audit timestamps

Recurrence Patterns

RRULE – Full recurrence rule support (Daily, Weekly, Monthly, Yearly)
Complex patterns with COUNT and UNTIL end conditions
By-day specifications (BYDAY) for weekly patterns
EXDATE – Exception dates for cancelled occurrences
RECURRENCE-ID – Modified occurrence tracking

Reminders & Alarms

VALARM – Display and audio alarms
Configurable trigger times (minutes, hours, days before event)
Multiple alarm support

Attachments

ATTACH – Inline BASE64 encoded file attachments
Proper line folding with TAB continuation for Outlook compatibility
VALUE=BINARY parameter for binary data
MIME type preservation (FMTTYPE)
Original filename metadata (X-FILENAME)
Configurable size limits (default 5MB per attachment)

Timezone Support

VTIMEZONE – Complete timezone definitions with DST rules
Automatic UTC to local time conversion
IANA timezone ID mapping from Windows timezone names
Support for timezones without daylight saving time
TZID parameter on date-time properties
Proper handling of PidLidTimeZoneStruct MAPI property

Additional Properties

CATEGORIES – Event categories (multiple tags supported)
URL – Associated web links
METHOD – REQUEST, PUBLISH, CANCEL, REPLY support

Technical Features

📏

RFC 5545 Line Folding

Automatic line wrapping at 75 characters with proper continuation using space or TAB characters for maximum compatibility

🌍

Full UTF-8 Support

Native handling of Cyrillic, Asian, and other Unicode characters in all text fields

🔒

Proper Text Escaping

Correct escaping of special characters (comma, semicolon, backslash, newline) per RFC 5545 requirements

⚙️

Configurable Export

Control inclusion of HTML descriptions, alarms, attachments, and other optional components

🎯

Smart Duplicate Detection

Automatic elimination of duplicate attendees and proper organizer handling

📱

Cross-Platform Compatible

Generated .ics files work seamlessly with Outlook, Google Calendar, Apple Calendar, Thunderbird, and more

Quality & Reliability

100% RFC 5545 Compliance

40+ MAPI Properties Mapped

7+ Calendar Apps Tested

0 Data Loss

Use Cases

📤 Calendar Migration

Migrate appointments from PST files to any calendar system supporting iCalendar format

💾 Backup & Archive

Create portable, standards-based backups of your calendar data

🔄 Cross-Platform Sync

Export from Outlook PST and import to Google Calendar, Apple Calendar, or any other platform

📊 Data Analysis

Extract calendar data for reporting, analysis, or compliance requirements

🔧 Integration

Integrate PST calendar data into custom applications and workflows

Download 32 bit version

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