Export Office 365 Mailboxes to .PST 

Export mailboxes from Office 365 to .pst files 

Roland Eich  Fri, Sep 6 2019  cloud computing, exchange, office 365  1  

Exporting mailbox items to a .pst file is the ideal way to migrate mailboxes or to perform an ad hoc backup. When Exchange is used in the customer’s datacenter, PowerShell can handle this task. In Office 365, however, the GUI from eDiscovery is provided for this, but it makes this process relatively complicated. 

Roland Eich 

Roland Eich is an IT specialist for system integration and has been working in IT for over 10 years as a system administrator. His areas of expertise are Windows Server and IT infrastructures. Certifications: MCITP EA, MCSA and MCSE. 

Contents of this article 

The first steps to preparing for a .pst export in Office 365 are the same as for an on-prem Exchange. You must first create the permission for the import and export function with: 

New-ManagementRoleAssignment -Role “Mailbox Import Export” -User <username> 

No cmdlets for .pst export in Office 365 ^ 

If you then look for the cmdlets for importing and exporting .pst files, you quickly realize they are not available in Office 365. 

Exchange’s well known cmdlets for importing and exporting .pst files are missing in Office 365 

Apparently, from Microsoft’s point of view, there seems to be no reason to migrate away from the cloud. As for backup purposes, there are dedicated programs like Veeam Backup for Office 365 or Altaro Office 365 Backup

However, there is a way for an administrator to export Office 365 mailboxes to a .pst file. The solution here is eDiscovery. This TechNet article contains basic information about this feature. 

Configuring eDiscovery ^ 

To use eDiscovery, log into the Office 365 portal (https://admin.microsoft.com or https://portal.office.com) and navigate to the Security & Compliance section. Alternatively you can directly enter the URL https://protection.office.com. Follow the Permissions link in the navigation pane. 

Open Security & Compliance in Office 365 

Select eDiscovery Manager from the permissions list. On the right-hand side, a window should now open in which you can configure this permission. 

Editing permissions for eDiscovery Manager 

First, you should check whether Export is included under Assigned roles. If not, the subsequent export to a .pst file will not be possible. 

Editing the list of eDiscovery administrators 

It is important to add any user who will later perform the export as the eDiscovery administrator. 

Adding an eDiscovery administrator for .pst export 

In the next step, select Content search in the left navigation bar under Search

Opening the overview for Content search 

Here you define a new search, and as a rule, you will not enter any keywords at this point. To avoid searching all of Office 365, it is advisable to limit the search to specific locations. We only want to search for mailboxes in Exchange and not get results from SharePoint or OneDrive. 

Configuring a new search for the .pst export 

Therefore, it makes sense here to activate the slider for Exchange email. Under Add Conditions, you can refine the search as much as you want, but this is not required for this scenario. 

Clicking on Save and Execute saves the search under a defined name. 

Saving an eDiscovery search 

After starting the search, you can go back to the overview. A short refresh will display the search job created earlier. 

Overview of search jobs 

If you click on it, the details of the job become visible. 

You can now start the export by clicking on the More button. 

Exporting the found mailboxes to a .pst file 

Here you can select different options on how to export the files. For example, you can specify whether to store each mailbox in its own .pst file or share a common file with others. For the purpose of this test, I have left everything as the defaults. 

Options for exporting mailboxes to a .pst file 

Now it seems the export depends on the browser you are using. With Google Chrome, I got a client error, and the export stopped. In Microsoft Edge, this problem did not occur. 

After clicking Export to complete the query, you can now click Export again in the upper bar to see the export job. If this does not display, you should refresh the browser window. 

Triggering the .pst file download in the export job details 

By clicking on the export job, you can now initiate the final save to local storage. 

Key the export tool will later require 

It is important that you copy or store the export key, as you will need it again later on. Click the Download results button to start the export. 

Microsoft Office 365 eDiscovery Export Tool setup 

This will launch the Microsoft Office 365 eDiscovery Export Tool setup. This is quite small and should install in a few seconds. The tool now asks for the export key you saved earlier and for a location for the .pst files. 

Enter the key in the Microsoft Office 365 eDiscovery Export Tool 

The export to the local computer will then start; it finished after a few seconds because my mailboxes are not that big. 

Successful download of exported .pst files 

My destination folder now contains the exported .pst files of my mailboxes. There are some additional reports about the export; however, they are not that significant.