In this article, I am going to show you how to export Office 365 mailboxes to PST files using an Office 365’s native in-place eDiscovery mechanism as a workaround.

The reason why you may need to use it is that Microsoft doesn’t provide any tools dedicated specifically for this purpose (like the New-MailboxExportRequest cmdlet in on-premises Exchange). In fact, if you want to export mailboxes to PST files to e.g. add a layer of extra protection to your Office 365 data or migrate away from Office 365, the eDiscovery mechanism is your only option, other than opening the mailboxes in Outlook and using its Import/Export functionality.

IMPORTANT: eDiscovery is supported in all Exchange Online plans and in selected Office 365 plans. For more see this TechNet article.

Note that this solution can also be used in Exchange 2016 and 2013.

System requirements:

  • 32 and 64-bit versions of Windows 7 and later versions
  • Microsoft .NET Framework 4.5
  • Internet Explorer 10 and later versions, or Mozilla Firefox or Google Chrome, with the ClickOnce add-in installed

As already mentioned, this is a workaround, so most of the below steps are going to be related to setting up in-place eDiscovery. The PST export comes at the end (it is performed via a ClickOnce application).

Steps to export Office 365 mailboxes to PST using eDiscovery

  1. In the Office 365 Admin center after logging in to your Office 365 portal, access the Security & Compliance Center as shown in the below image.Accessing Office 365 Admin Center
  2. In your Office 365 admin center, expand Admin centers and click Security & Compliance.
    Access Office 365 Security & Compliance Center
  3. In your Security & Compliance center, go to Permissions and edit eDiscovery Manager role group.
    This and the next step are necessary because you need to be a member of the eDiscovery Manager role group to be able to use eDiscovery features.
    Set Permissions to Export Mailboxes to Office 365
  4. In the eDiscovery Manager role group properties window, add your account to the eDiscovery Administrator list using the plus button and click Save.The role group normally has the following roles assigned: Case ManagementCompliance SearchExportHoldPreviewReview and RMS Decrypt. In some cases, the Export role is missing. If that is the case, make sure you add it using the plus button.Setting Permissions to eDiscovery Management
  5. Now go to Search & investigation, click the plus button to start a new Content Search wizard, type in a name and click Next.
    Create New Content Search in Office 365 eDiscoveryImportant note: If you are missing the + button, it is most likely related to the eDiscovery permissions you set in the previous steps. Changes in the eDiscovery permissions might take even up to 24 hours to apply. 24 hours after you set the permissions (or less, in my case it was around an hour) the tool should work just fine. The issue with permissions might also result in the lack of the download button in step 9.
  6. If you want to export data from all mailboxes, select Search everywhere and tick Exchange.Or select specific mailboxes using the Custom location selection option, and then clicking the plus button. This will open a new window – highlight the mailboxes and/or SharePoint sites you want to export data from, click add -> and OK.Additionally, you can enable exporting from Public folders by checking the Search all public foldersoption (in the Public folders section at the bottom of the window)Choose Office 365 mailboxes to export to PST
  7. The next step gives you several filtering options (unless you want to export all data, in which case do not change anything):
    • keywords/phrases (separated by logical operators: AND, OR, NEAR, NOT, etc.)
    • time ranges
    • From/To/CC/BCC fields
    • and message types (which can be defined in the window that opens when you click the select message types… button).

    eDiscovery Search - Specify keywords and conditions

  8. After clicking Search, the wizard will perform the search in the background. When it finishes click Start export.
    Export Office 365 Mailboxes to PST files
  9. In the window that pops up, you can choose if you want to include encrypted files. You can also decide how to export the Exchange content. I find the default options to be the most reasonable for a backup – each mailbox has a separate PST file, which makes recovery a bit easier if necessary. When you are finished, click Start export on the bottom of the window.How to Export Office 365 Mailboxes to PST
  10. The wizard starts to export data. You can either wait for it to finish, or click Download exported results right away. If you start to download the results before the export is completed, the download and export tools should finish at the same time.Download exported results
  11. In this window, a special export key is generated. Remember to copy it, as it will be required in the ClickOnce application that will start in the next step.Copy the export key to clipboard
  12.  A ClickOnce application called eDiscovery PST export tool will start. Paste the export key copied in the previous step. Next, point it the Export tool to a folder where you want to save the PST files.
    Paste the export key and point to the download location
    Do not check the Enable deduplication option, unless you want the search results to be exported to a single PST file.For more on unsearchable items see this TechNet article.

After you click Start, the tool will begin the export. When it completes, close the application.


Back up Office 365 with CodeTwo Backup for Office 365


After performing the export, you can delete the eDiscovery search from the Content Search window by highlighting it and clicking the trash button.

Export Office 365 mailboxes to PST using CodeTwo Backup for Office 365

If you are looking for an easier and faster way of creating PST files that playing with an eDiscovery search and export, you can use a third party solution like CodeTwo Backup for Office 365. The program comes with the intuitive console, where you can first back up your mailbox data to local storages, and then archive it to PST files.

Archive to PST

As the program has the built-in Scheduler, you can easily automate the archiving process. This way the archive job will start on its own at the scheduled time.

Scheduler option

The program comes with a trial so you can download a free version of CodeTwo Backup for Office 365 and test it directly in your environment. The trial version gives you actually the same feeling as the full version with only two limitations – it works 30 days and allows to restore up to 5 items per folder (if you would like to test the restore feature as well).

All in all, using PST files as the backup method is rather a bad idea. Their proneness to corruption, low to none item-search effectiveness, and poor management options make this method rather unsafe and hazardous for backup or migration purposes.