To pull emailed invoices and receipts out of an old Outlook PST, open the PST read-only, filter it by the tax year’s date range plus words such as invoice, receipt or statement in the subject or body, check the results, and export them as one bookmarked PDF with the attachments added as pages and the original files saved beside it. PstVault, a Windows app from Automata Labs, does this without Outlook and without uploading the mailbox, and every export comes with a report listing each file it wrote and its SHA-256 hash.
The situation is common. A tax authority asks for support for expenses from a year when the business used a different email setup. An accountant needs every supplier invoice for a fiscal year. A bookkeeper inherits a client whose old mail now lives only in an archive file on a backup drive. The documents exist; they are just inside a file Windows cannot open on its own.
Search an old PST by date and subject, then export the invoices you find as one bookmarked PDF.
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How long do you need to keep emailed invoices and receipts?
Retention rules are why this comes up years later. Two examples, from the tax authorities’ own pages:
| Jurisdiction | General rule | Source |
|---|---|---|
| Canada (CRA) | Keep required records and supporting documents for six years from the end of the last tax year they relate to, with longer periods in some situations | CRA: how long to keep your records |
| United States (IRS) | Keep records until the period of limitations for the return runs out, generally 3 years, and longer in specific cases such as 6 or 7 years, or indefinitely | IRS: how long should I keep records |
The CRA page lists situations with longer or different periods, and points to Information Circular IC05-1, Electronic Record Keeping, for how electronic records should be kept. This article is not tax advice; your accountant decides what support a return needs. The practical point is that an invoice received by email in a year that is still open is a record you may be asked for, and the PST may be the only copy left.
Why is a PST awkward for this job?
A PST holds everything: the invoices, but also newsletters, shipping notices, replies and years of unrelated mail, all in one file. The usual routes each have a catch:
- Attach it to Outlook. It works if you have classic Outlook installed and licensed, but the archive is now attached to a working profile, and moving or deleting items changes the file. Our page on opening a PST in new Outlook covers the current requirements.
- Upload it to an online converter. A mailbox full of supplier invoices also holds bank details, addresses and customer correspondence.
- Convert the whole file. Turning every message into PDF produces thousands of pages that someone then has to sort.
What the job actually needs is a search, a review and a targeted export, from a copy of the archive that stays unchanged.
What search terms find invoices in a PST?
Invoices rarely share one subject line, so search in layers. Start with the date range, then narrow by words that suppliers use:
| Filter | Example | Why |
|---|---|---|
| Date range | The fiscal year, for example 1 Jan to 31 Dec | Keeps the result to the year being reviewed |
| Subject words | invoice, receipt, statement, order confirmation, payment | Catches most automated billing email |
| Body words | invoice number, amount due, paid, GST, HST, VAT, tax | Catches invoices with generic subjects such as “Your documents” |
| Sender | A known supplier’s billing address | Collects everything from one vendor |
| Recipient | accounts@ or the bookkeeper’s old address | Finds invoices that went to a shared inbox |
Run one search per supplier or per term and review each set. It is faster than one broad search that returns half the mailbox.
How do you export the invoices with PstVault, step by step?
- Work from a copy. Copy the PST from the backup drive to your PC. PstVault opens it read-only either way, but a copy keeps the backup untouched.
- Open the PST. Choose Open PST, or double-click the file in File Explorer. PstVault shows every folder with its message count.
- Pick the scope. Select All folders, or a folder and everything beneath it, such as Inbox and its subfolders.
- Filter. Type in Subject or Sender, or open More filters for Body, Recipient, From date and To date. Content search can be cancelled if you started too broad.
- Review. Click through the results in the preview. Each item shows its headers, its folder and its attachments; a supplier’s PDF can be saved from the preview on its own.
- Select and export. Select the invoices you want and choose the PDF reading copy. Pick one PDF with a bookmark per item, or one PDF per item, on Letter or A4.
- Choose how the attachments travel. Append supported PDF, PNG, JPEG and TXT attachments as printable pages, embed the originals in the PDF, save them as loose files beside it, or combine these. The options are independent.
- Check the report. Every export writes a JSON report with the source, the filters behind the selection, each item with its format and output file, and the size and SHA-256 hash of every file written. Items are marked Complete, Partial, Failed or NotProcessed, so you can see what needs attention before you send anything.
Files are named by date and subject, and existing files are never replaced, so a second run for another supplier does not overwrite the first.
Hand your accountant one bookmarked PDF of the year’s invoices, with the original attachments kept.
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Which format should you hand to an accountant or auditor?
It depends on who reads it and what they do with it:
| Recipient need | Best export | Why |
|---|---|---|
| Read and tick off invoices | One bookmarked PDF with attachments appended as pages | One file, one bookmark per email, invoice pages inline |
| Re-key amounts into software | PDF plus the original attachments saved as files | The supplier’s own PDF is easier to read and copy from |
| Keep the emails as emails | EML files with attachments inside | Opens in standard mail apps with headers intact |
| Show what was exported and when | The JSON report | Lists every file with its SHA-256 hash |
Our comparison of EML, PDF and HTML for exported email goes deeper on the trade-offs, and the PST to PDF page shows the PDF options. If you need the supplier attachments only, the guide to extracting attachments from a PST covers that route.
What should you check before sending the bundle?
- Gaps in the year. Sort the results by date. A supplier billed monthly should show twelve invoices; a missing month may be in another folder or another archive.
- Partial items in the report. A message marked Partial may have an attachment type that could not be appended as pages. Save that original file separately.
- Duplicates. Forwarded invoices appear twice, once from the supplier and once from whoever forwarded them.
- Private mail. If the archive mixes business and personal mail, review each item before export. Exporting selected messages is the whole point.
- Hashes, if anyone asks later. The SHA-256 values in the report let you show that a file you send next year is the same one you exported today. Our guide to checking a SHA-256 hash with certutil shows how to compare one.
What PstVault cannot do
PstVault is designed for readable Unicode PST files, one archive at a time, the kind Outlook 2003 and later create. It does not open OST files, repair damaged archives or decrypt encrypted messages. PDF and HTML exports are reading copies, and their formatting may differ from the original message. Body processing, attachments and PDF page counts have limits, which is why the report flags partial results. It also does not read amounts or totals out of invoices; it finds and exports the emails, and the bookkeeping happens in your accounting software.
Frequently asked questions
Can I search a PST for invoices without Outlook?
Yes. PstVault reads the PST directly and filters by sender, recipient, subject, body text and a date range, with no Outlook installation and no mail profile.
Will searching or exporting change the PST?
No. PstVault opens the PST read-only and writes only new output files, so the archive stays as it was.
Can I get the invoice PDFs themselves, not just the emails?
Yes. Save original attachments as separate files beside each message, embed them in the exported PDF, or append supported PDF, PNG, JPEG and TXT attachments as printable pages. You can combine these options.
Is anything uploaded?
No. Mail processing happens on your PC. PstVault does not upload email or connect to a mail server. If you save exports into a folder that Windows syncs to the cloud, that sync is separate from PstVault.
Does this replace advice from my accountant?
No. PstVault finds and exports the records. What a return or audit needs, and for how long you must keep it, is a question for your accountant and the tax authority’s guidance.
Try PstVault
PstVault is a one-time purchase in the Microsoft Store, with a 15-day free trial of every feature. Open the old archive, run a search for one supplier and one year, and export a bookmarked PDF before you buy. More detail is on the PstVault product page, and our guide to exporting emails from a PST covers the other formats.
Find one year of invoices in an old PST during the 15-day free trial.
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Microsoft and Outlook are trademarks of the Microsoft group of companies. PstVault is not affiliated with or endorsed by Microsoft, the CRA or the IRS. This article is not tax or legal advice.
Last updated 19 October 2026. Published by Automata Labs, a software company in Canada.