Help Guide

How to Export Messages from Microsoft Purview eDiscovery

Complete step-by-step guide to export Microsoft 365 archived emails using Purview Content Search or eDiscovery. Covers the Export key, the Purview Export Tool (ClickOnce), PST output options and the Azure staging process.

📅 Updated: March 2026 ⏲️ 8 min read ✓ Verified with Microsoft Purview compliance.microsoft.com
Quick Answer

compliance.microsoft.com → Content Search → New search → add mailboxes → run → Export tab → Export results → copy Export key → Download results → paste key into Export Tool → choose folder → Start. Purview stages data to Azure first — allow hours for large archives. The Export key is shown only once; copy it immediately. Need to convert the output PST? Use Univik Microsoft Purview Converter.

You cannot download exports directly from the browser. Purview stages all export data to temporary Azure Blob Storage. You must run the Purview Export Tool — a separate ClickOnce Windows application — and authenticate it with a one-time Export key. The tool only works on Windows and requires Microsoft Edge in IE Mode or Internet Explorer to launch.

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Who can export from Purview? You need the eDiscovery Manager or eDiscovery Administrator role. Global Admins are not automatically eDiscovery Managers — assign roles at compliance.microsoft.com → Roles & scopes → Role groups. Managers access only their own cases; Administrators access all cases.
1

Open the Microsoft Purview Compliance Portal

Sign in at compliance.microsoft.com with your eDiscovery account

Go to compliance.microsoft.com and sign in with an account that has the eDiscovery Manager or eDiscovery Administrator role assigned. All export operations live here.

Microsoft Purview Compliance Portal — Left Navigation
Compliance Portal
ED
ediscovery.mgr@company.com
Solutions
Content search
eDiscovery (Standard)
eDiscovery (Premium)
Audit
Data loss prevention
Content search
Select a search or create a new one to begin.
4

Export the Search Results

Click the Export tab and configure PST output format and deduplication

With the completed search selected, click the Export tab, then Export results. The configuration panel opens. Choose output scope, PST format and whether to enable deduplication. Click Export to submit the job.

Purview — Export Results Configuration Panel
ED
Search statistics
Export
Output options
Export Exchange content as
Other options
One PST per mailbox is the best choice for migration. It creates one named PST per user (e.g. john@company.com.pst) that maps directly to a mailbox when importing via the Microsoft 365 Import Service. Always enable deduplication to prevent the same message being imported twice.
5

Copy the Export Key

One-time authentication token — copy it immediately before navigating away

After clicking Export, Purview shows the Export key — a long alphanumeric token that authenticates the Export Tool. Copy it immediately and save to a text file. It is shown only once. If you navigate away without copying it, delete the job and re-submit to get a new key.

Purview — Export Key Shown After Job Submission (copy before leaving this screen)
ED
Export job created successfully.

Purview is staging data to Azure temporary storage. This may take several hours. When the Export tab shows The export is complete, click Download results and paste the Export key into the Export Tool.

Export Key — shown once only, copy now
MIIBvAIBADAsBgkqhkiG9w0BAQEFAASBmDCBiQKBgQC4tH9kX3cNp7Wq2mR8sLv... [full key truncated for display] ...GbEuCjA==
This key will not be shown again. Copy it before navigating away.
The Export key is shown once only. If you navigate away before copying it, you must delete the export job and re-submit. Save it to a text file immediately. It is a long base64 string — copy the entire value.
Wait for Azure staging before clicking Download results. After job submission, Purview stages all data to Azure Blob Storage first — for a 100 GB archive this takes 4–8 hours. Do not click Download results until the Export tab shows The export is complete.
6

Run the Purview Export Tool

Launch the ClickOnce tool, paste your Export key and start the download

When the export shows complete on the Export tab, click Download results. This launches the eDiscovery Export Tool via ClickOnce. If nothing happens, enable Edge IE Mode first (see Troubleshooting #1). Once open, paste your Export key, choose a local folder and click Start.

The Export Tool requires Edge in IE Mode or Internet Explorer. Chrome, Firefox and standard Edge will not launch it. In Edge: Settings → Default browser → Internet Explorer compatibility → add compliance.microsoft.com to the site list. Reload the portal in Edge and click Download results again.
eDiscovery Export Tool — Windows ClickOnce Application
eDiscovery Export Tool
C:\Users\admin\Desktop\PurviewExport
Downloading…14.2 GB / 38.7 GB
john@company.com.pst (4.7 GB)  •  sarah@company.com.pst (9.5 GB)  •  mike@company.com.pst (in progress)

What is in a Microsoft Purview Export?

The Export Tool downloads files into your chosen folder. Every export includes PST (or MSG) files alongside supporting CSV and manifest files for audit and completeness verification.

Purview Export Folder — One PST per Mailbox
C:\Users\admin\Desktop\PurviewExport\ 38.7 GB
├ john@company.com.pst │ 42,814 messages, 14.8 GB ├ sarah@company.com.pst │ 38,291 messages, 13.1 GB ├ mike@company.com.pst │ 29,107 messages, 10.1 GB ├ Results.csv │ Every item: mailbox, subject, date, size ├ manifest.xml │ Chain-of-custody: links items to source locations ├ Exchange.NonIndexedItems.csv │ Items Purview could not index — review for gaps └ [PST files import directly into Outlook or the Microsoft 365 Import Service]
PST optionOutput filesBest for
One PST per mailboxuser@domain.pst per userMicrosoft 365 Import Service, per-user migration
One PST for allSingle combined PSTSmall exports, quick review in Outlook
Individual messagesOne MSG per emailLegal review, per-document production
Always includedResults.csv, manifest.xml, NonIndexedItems.csvAudit trail, completeness verification

Convert Purview PST Exports to MBOX, EML or PDF

Purview PST files open directly in Outlook. For other destinations — MBOX for Thunderbird, EML for individual messages, or PDF for compliance records — Univik Microsoft Purview Converter handles all Purview PST patterns:

  • Thunderbird / Gmail — Convert per-mailbox PST to MBOX format
  • Legal / Compliance — Convert to PDF with manifest.xml chain-of-custody preserved
  • Per-message output — Convert PST to individual EML or MSG files
  • Repair — Normalise Purview PSTs that fail Outlook import
Univik Microsoft Purview Converter

Convert Purview PST exports to MBOX, EML, PDF and 10+ formats. Preserves manifest.xml. Handles per-mailbox PST patterns. 100% offline.

⬇️ Free Download Learn More →
Frequently Asked Questions
Why do I need the Export Tool? Can I just download from the browser?
No. Purview stages all export data to Azure Blob Storage first. There is no direct browser download path. The eDiscovery Export Tool is the only supported method — it is a ClickOnce Windows application that authenticates to Azure using your Export key and streams the files to your machine.
What format does Purview export email in?
Purview exports as PST in three variations: one PST per mailbox (recommended), one combined PST for all mailboxes, or individual MSG files per message. Every export also includes Results.csv, manifest.xml and Exchange.NonIndexedItems.csv. The manifest provides chain-of-custody verification linking each exported item to its source location in Microsoft 365.
What is the Export key and what happens if I lose it?
The Export key is a one-time authentication token shown immediately after job submission. It is shown only once. If you navigate away before copying it, you cannot retrieve it — go to the Export tab, delete the export job and click Export results again to get a new key. Save it to a text file immediately after copying.
Why is the Export Tool not launching when I click Download results?
The Export Tool uses ClickOnce technology that only works in Internet Explorer or Microsoft Edge with IE Mode enabled. Chrome, Firefox and standard Edge will not launch it. In Edge go to Settings → Default browser → Internet Explorer compatibility and add compliance.microsoft.com to the IE mode sites list. Reload the compliance portal in Edge and click Download results again.
Why is my Purview export taking many hours?
The process has two phases: Azure staging (Purview packages all data on Microsoft's side — can take hours) then Export Tool download (throughput is throttled to roughly 2 GB/hour). For a 50 GB archive, plan for 4–8 hours of staging followed by 10–25 hours of downloading. Run large exports overnight and leave the Export Tool running in the background.
What roles are required to export from Microsoft Purview?
You need the eDiscovery Manager or eDiscovery Administrator role assigned explicitly in the Purview compliance portal. Global Admins do not have these roles automatically. Assign them at compliance.microsoft.com → Roles & scopes → Role groups → eDiscovery Manager. Managers can only access cases they own or were added to; Administrators can access all cases organisation-wide.
What is in the NonIndexedItems.csv file?
This file lists all items in the search scope that Purview could not index — encrypted attachments, password-protected Office files, corrupted messages and certain image types. These items are not in the main PST. Review this file to check for gaps in your export. If non-indexed items are required (e.g. for legal production), use the output option "Also include items that have an unrecognized format, are encrypted, or weren't indexed" when configuring the export.
Troubleshooting Common Issues
1 Export Tool does not launch when I click Download results

The ClickOnce Export Tool requires Internet Explorer or Edge in IE Mode. In Edge go to Settings → Default browser → Internet Explorer compatibility and add compliance.microsoft.com to the IE mode site list. Reload the compliance portal in Edge and click Download results again. Alternatively, look for a direct download link on the same page — it lets you download the ComplianceCaseTool.application installer manually and run it from File Explorer without needing IE mode.

2 Export key is invalid or authentication fails in the Export Tool

Each Export key is single-use and expires. If the Export Tool returns an authentication error, the key was already used or has expired. Go to the Export tab, delete the existing export job and click Export results again to generate a new key. Copy the new key immediately. Even if a previous download was interrupted, the key is consumed and a new one is required.

3 Export status stuck on "The export is being prepared"

Azure staging can take a very long time for large archives. Refresh the Export tab every 30 minutes. If status has not changed after 24 hours with no error shown, raise a support ticket with Microsoft 365 Support via admin.microsoft.com referencing the export job name and creation timestamp. Also confirm the underlying search completed successfully — if any mailboxes had search errors, the export may stall waiting for those locations.

4 Export Tool download interrupted halfway

If the download is interrupted, you cannot resume with the same Export key. Delete the export job, re-submit a new export, copy the new key and restart the Export Tool. To prevent interruptions: disable sleep and hibernate on the download machine, use a wired network connection, do not close the Export Tool window while running and ensure the destination drive has enough free space before starting.

5 Exported PST cannot be opened or imported into Outlook

Run the PST through the Outlook Inbox Repair Tool first: C:\Program Files\Microsoft Office\root\OfficeXX\scanpst.exe. If scanpst does not resolve the import error, use Univik Microsoft Purview Converter to extract and re-package the PST content into a clean output file that Outlook accepts without errors.

Need to Convert Your Purview PST Export?

Convert Purview PST exports to MBOX, EML, PDF and 10+ formats. Preserves manifest.xml. Handles per-mailbox PST patterns. 100% offline.

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About This Guide

This guide is written and maintained by the Univik team, developers of file conversion and digital forensics tools since 2013. We verify each guide against the latest version of each platform. Last verified: March 2026 with Microsoft Purview compliance.microsoft.com.

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