How to Archive an Outlook PST as Searchable PDFs, Attachments Included

The short answer

To archive an Outlook mailbox as PDF without Outlook, use a converter that reads the .pst file directly, writes each message as searchable text, and keeps attachments as real files rather than dropping them. reaConverter, a Windows batch converter from ReaSoft Development that handles 800+ formats, can convert PST to PDF with every original attachment embedded inside the document, so the recipient opens one file and finds both the emails and the evidence.

Keep the original PST next to the PDFs. The PDF is the copy people read; the PST is the record you may need to produce later.

When does a PST need to become PDF?

A PST file is Outlook’s local mailbox container. It works fine inside Outlook and becomes a problem the moment someone outside Outlook needs the mail. Five situations account for most requests:

• An employee leaves. IT exports the mailbox before the license is reclaimed, and nobody can read the export later without loading it back into Outlook.
• A legal hold or dispute. Outside counsel asks for a custodian’s email, and the attachments, such as contracts, invoices, and spreadsheets, are the actual evidence.
• Retention rules. Policy or regulation requires mail to be kept for a set number of years in a format that will still open.
• A business closes or is sold. The buyer, the liquidator, or the accountant needs the mail, not the Outlook profile.
• A records or public information request. The requester does not run Outlook and should not have to.

In every case the hard part is the same. The email body is easy to print. The attachments are where things get lost.

Why PDF, and not PST, MSG, or EML?

Each mailbox format answers a different need. PDF wins when the reader is a person who just needs to read, search, and keep the record.

Format	Opens in	Attachments	Searchable	Good for
PST	Outlook	Inside the container	Only inside Outlook	Moving a mailbox between Outlook installs
MSG	Outlook	Inside each message file	Only inside Outlook	Single messages saved from Outlook
EML	Most mail clients	Inside each message file	In a mail client	Moving mail between different email programs
PDF	Any PDF reader, any device	Embedded as original files, if the tool supports it	Yes, as text	Review, sharing, and long-term records
PDF/A	Any PDF reader	Depends on the PDF/A level used	Yes	Records that must stay readable for decades

PDF also looks the same to everyone who opens it. That matters when the mail is evidence or a formal record, and a reviewer must see exactly what the sender saw.

Which tools turn a PST into PDF?

The options split on two questions: do you need Outlook installed, and what happens to the attachments?

Tool	Needs Outlook	Batch	Attachments	Watch out for
Outlook print to PDF	Yes	No, one message at a time	Not included in the PDF	Fine for a handful of emails, impractical for a mailbox
Acrobat Pro add-in, classic Outlook	Yes, plus an Acrobat subscription	Whole folders, as a PDF Portfolio	Kept inside the Portfolio	In the new Outlook for Windows, users report it converts one email at a time
Dedicated PST converters	No	Yes	Varies: embedded, flattened, or saved to a side folder	Licensing is often per mailbox or per seat
E-discovery platforms	No	Yes	Full handling with metadata	Built and priced for law firms and large legal teams
reaConverter	No	Yes, plus Watch Folders and command line	Embedded as original, openable files	Windows only; automation needs the Pro edition

The attachment column is the one to test before you buy anything. Convert one real mailbox, open the result, and check that a contract or spreadsheet can be opened from inside the PDF as the original file.

How to convert a PST to PDF in reaConverter

reaConverter opens .pst files directly, both older ANSI and current Unicode ones, and never starts Outlook. Everything runs offline, which is what you want with confidential mail.

1. Add the PST. Drag the file into the main window, use Add Files, or right-click it in Windows Explorer and convert from the context menu.
2. Choose PDF. Set the output format to PDF. Attachments are embedded automatically; there is nothing to switch on.
3. Decide on archive settings. The PDF settings behind the gear icon offer Create PDF/A document for long-term records and a Document Open password for sensitive mailboxes.
4. Convert. Click Convert. The log shows progress message by message.
5. Check the result. Open the PDF in Adobe Acrobat Reader. The message text is searchable, and the Attachments panel, behind the paperclip icon, lists every original file.

GUI conversion works in the Standard edition. For an IT team that archives mailboxes every week, reaConverter Pro adds a command-line tool, so an offboarding folder can be processed on a schedule:

cons_rcp.exe -source_folder “D:\Offboarding\PST\” -source_ext pst -dest_path “D:\Offboarding\PDF\” -dest_ext pdf -create_pdf_a 1 /hide

Append > “D:\Offboarding\log.txt” to keep a record of each run.

Checklist before you hand the PDFs over

A converted mailbox often ends up in front of a lawyer, an auditor, or a buyer. A few minutes of checking prevents an awkward follow-up.

• ☐ Hash the original. Record a checksum of the PST before conversion. On Windows, certutil -hashfile mailbox.pst SHA256 does it with no extra software, and proves later that the source was not changed.
• ☐ Keep the PST. Store the original next to the PDFs. Some requests will eventually ask for native files.
• ☐ Spot-check attachments. Pick five messages with attachments and open each file from the PDF.
• ☐ Search the text. Search for a name or invoice number you know is in the mailbox. If it is not found, something went wrong.
• ☐ Remove what should not go. Privileged messages, personal mail, and unrelated folders may need to be excluded before handover.
• ☐ Protect it in transit. Use a PDF open password or an encrypted channel, and send the password separately. PDF/A files cannot be encrypted, so protect those at the storage or transfer level.
• ☐ Note the time zone. Message timestamps depend on the settings of the machine that converted them. Write down which one you used.

Honest limitations

• Not a substitute for an ESI protocol. In formal litigation, productions often have to follow an agreed format, sometimes native files plus load files. A PDF archive is ideal for review and records, but check what the other side or the court requires.
• PDF/A and attachments. Earlier PDF/A levels do not allow arbitrary embedded files; only PDF/A-3 does. If you need both strict PDF/A compliance and embedded attachments, validate a sample file first.
• Password-protected PST files. Remove the password in Outlook before converting. A protected container cannot be read without it.
• Very large mailboxes. Multi-gigabyte PST files take longer and use more memory. Run them overnight or one at a time.
• Viewer support. Some lightweight and in-browser PDF viewers do not show embedded attachments. The files are still there; Acrobat Reader displays them.
• reaConverter specifics. Windows only. Watch Folders and the command line require the Pro edition.

FAQ

Can I convert a PST file to PDF without Outlook? Yes. Tools that read the PST format directly, such as reaConverter, convert it without Outlook, Exchange, or an internet connection.

How do I keep email attachments when converting to PDF? Use a converter that embeds attachments as files inside the PDF. Outlook’s print to PDF does not include them. In Acrobat Reader, embedded files appear in the Attachments panel.

What is the best format for archiving old email? For records people will read, PDF or PDF/A. Keep the original PST as well, in case native files are ever requested.

How do I archive a departing employee’s mailbox? Export the mailbox to PST, record a checksum, convert it to searchable PDF with attachments, and store both files under your retention policy.

Can I open a PST file on a computer without Outlook? Not natively in Windows. You need a PST viewer or a converter that reads the format directly and turns it into something any computer can open.

About the author

Jordan Blake writes about document and email conversion for the reaConverter team and maintains the guides at howto.reaconverter.com. Jordan’s focus is the records that outlive the software that created them.