PST Inspector – Free Outlook PST & OST Viewer

Open PST, OST, MSG and EML files without Outlook

PST Inspector is a free Windows program that opens Outlook data files (.pst, .ost) and single messages (.msg, .eml) without Outlook, Office or MAPI. It shows the mailbox the way Outlook does – folders, mail, contacts, calendar, tasks, notes – and, for specialists, everything underneath: properties, named properties and the raw structure of the file. Nothing is ever written to your data file.

Version 0.9.9.19 · Windows 10 / 11, 32-bit and 64-bit · no installation · 100% free, no trial, no limits.

Key features

Open PST and OST files without Outlook

• ANSI (Outlook 97–2002) and Unicode (Outlook 2003 and later) data files, .ost files of Exchange / Microsoft 365 accounts, the 4K page layout, compressible and high encryption.
• Single .msg and .eml files; open by File > Open, drag & drop, the command line or the recent files list.
• Read-only: the data file is never changed.

Read mail like in Outlook

• Folder tree with item counts and special folders; system and hidden folders on request.
• Reading pane on the right or below the list, and message windows of their own (several at once).
• HTML, RTF and plain text bodies, inline pictures, internet headers, recipients and attachments; remote pictures only on request.
• Contacts as business cards, calendar with recurrence, tasks, journal and coloured notes.

Search the whole PST file

• Find in file: words in subject, sender, recipients and body, item kind, date range, attachments; results while the search runs, Show in folder.
• Filter every list while you type; sort by any column.

Export PST messages to MSG and EML

• Save a message as .msg (all properties and attachments) or .eml (MIME); contacts as vCard 2.1 / 3.0 / 4.0, appointments as iCalendar (RFC 5545).
• Export many messages: the selection, a folder or a folder tree, in the background, with a summary at the end.
• Print and print preview; lists as CSV / TSV; properties as a JSON property dump; Ctrl+C on every list.

Signed and encrypted messages

• S/MIME and OpenPGP (PGP/MIME and inline PGP): signature check, decryption with your certificates and keys, decrypted .msg copies.

For IT, forensics and data recovery

• Every property of folders, messages, recipients and attachments, including calculated properties; the named property map (PidLid / PidName names).
• RAW Data: the node and block B-trees of [MS-PST], block inspector (hex, binary, trailer), file header, Go to NID / BID, B-tree consistency check.

Comfortable

• Light and dark styles, window layout remembered, keyboard shortcuts, daily update check, the online User Guide (Help > User Guide, F1).

Every window and command is described in the PST Inspector User Guide – for example the reading pane, Find in file, exporting many messages, signed and encrypted messages and the RAW Data page.

Who is PST Inspector for?

• IT administrators and support engineers – look into a mailbox file, find a message and export it without setting up Outlook.
• Forensics and security specialists – examine content, attachments, hidden folders and properties; the file is opened read-only.
• Data recovery experts – read damaged or orphaned PST / OST files down to the raw blocks.
• Power users – open an old archive, read it, print it, save messages as .msg / .eml.
• Developers and system integrators – check MAPI properties and named properties while building your own tools.