Do you need to export an all of your Microsoft 365 / Office 365 email boxes to a PST file for backup or migration?

How to Export 365 email for backup or migration in 2025.

This is how to do it one mailbox or an entire organisation/tenant.

Preparation Step 1:

Sign into your admin.microsoft.com administration panel using EDGE browser.

Preparation Step 2:

Assign the global administrator account that you are using ‘eDiscovery Manager’ permissions as a Manager not Administrator by following this video that shows you how inside the purview.microsoft.com/settings/purviewpermissions section :
https://www.youtube.com/watch?v=fc9-7fWhX3o
Remember only to add rights as ‘eDiscovery Manager’ – don’t include the ‘eDiscovery Administrator’ rights otherwise it won’t work.
You may need to wait 10 to 30 minutes for this to take effect.

Export Office 365 Emails to PST Using eDiscovery Search

To export an Office 365 mailbox to a PST file using the eDiscovery feature in the (New 2025) Microsoft Purview Compliance Portal:


Step 1: Access the Microsoft Purview Compliance Portal

  1. Sign in to the Microsoft Purview Compliance Portal.
  2. In the left navigation pane, go to Content search (located under Solutions -> eDiscovery).

Step 2: Create a Content Search

  1. Click New search.
  2. In the New search pane, enter a name for the search (example: “Export Mailbox User XYZ”).
  3. Under the Locations section, select Specific locations.
  4. Choose Exchange mailboxes and specify the user’s mailbox you want to export.
  5. If needed, refine your search by adding filters such as date ranges, keywords, or message types in the Conditions section.

Step 3: Run the Search

  1. Click Save & run to start the search by clicking on the newly created search and in the slide out panel clicking ‘Actions’ -> ‘Export Results’.
  2. When the side panel opens – Choose top options ‘All items’ and Export Exchange content as ‘One PST file for each Mailbox’ – then Export button at the bottom and it will say an export job has been created.
  3. Monitor the search progress under the Content search tab.
    Look under the ‘tab’ that says ‘Export’ – Click the item to see details of the search process.
  4. Once the search is complete (hit the refresh button) select ‘Download Results’.

Step 4: the Export

  1. Once the search is complete (hit the refresh button after a while) – select ‘Download Results’.
  2. Configure the export settings: (You probably won’t need any of these)
    • Output options: Choose All items, including those with unrecognized formats, encryption, or that weren’t indexed.
    • Export format: Select PST file (this is the default option for mailbox items).
    • Optionally, specify a size limit for the PST file.

Step 5: Download the Export

  1. After the export process is finished, click Download export results.
  2. Download and run the Microsoft-provided eDiscovery Export Tool!
    Important click RUN on the new download in EDGE (its not your PST file just yet)
  3. Use the export key (provided in the Compliance Portal) to authenticate and begin the download when the eDiscovery Export Tool opens.
    The Export Tool will be open in front of the browser. Simply go back to the browser and copy the ‘Export Key’ shown under the download results section.

Step 6: Save the PST File

  1. The eDiscovery Export Tool will download the PST file to your system.
  2. Don’t forget to set the download location in the eDiscovery Tool.
    Note that it can take quite a long time before the actual download starts.. so be patient!


By following these steps, you will successfully export all your email from Office 365 to a PST file, ready for backup or migration.



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