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Export Office 365 mailbox to PST

We have to export an Office 365 mailbox to PST file. An excellent way to accomplish this task is to use the Microsoft 365 compliance center and export the Office 365 mailbox to PST. Microsoft provides the compliance center, and it’s free. So why not use that instead of paying for a third-party tool to export Office 365 mailboxes to PST files. In this article, you will learn how how to export a PST file from Office 365.

Before you start

Exporting an Office 365 mailbox is different than exporting an Exchange on-premises mailbox. Are you looking at how to export an Exchange on-premises mailbox to PST file? Read the article: Export Exchange mailbox to PST with PowerShell.

Export PST file from Office 365 using eDiscovery

To export Office 365 mailbox to PST file, follow the steps below.

Step 1. Assign eDiscovery permissions

As an administrator, we have the Global admin role in the organization. But, that does not mean we have the permissions to search through mailboxes and export the results. To have access, we have to check if the permissions are set. If not, we will add them to the role group eDiscovery Manager.

Note: Set the permissions in the compliance center. Otherwise, you can’t create a content search and export the mailbox to PST file.

Sign in to Microsoft 365 compliance center. Click in the navigation on Permissions. Expand Compliance center and click on Roles.

Read more: Microsoft 365 security and compliance center improvements »

Microsoft 365 compliance permissions & roles

Search for ediscovery. Click in the results on eDiscovery Manager.

Compliance center roles search for eDiscovery

Check that the Assigned roles for eDiscovery Manager are present. If not, add these roles. After that, add the administrator account to the Discovery Administrator. Click Close.

Note: It can take up to 24 hours before the change applies. But, most of the time it will work within 1 hour.

eDiscovery Manager role

In the next step, we will create a content search.

In the Microsoft 365 compliance center, click on Content search > Search > New Search.

New content search

Add the name of the mailbox. Click Next.

Name and description

Turn the switch to On for Exchange mailboxes. Click on Choose users, groups, or teams.

Specific locations

Search for the Exchange mailbox. The loading can take a little bit of time.

Search for Exchange mailbox

Select the Exchange mailbox. Click Done.

Select Exchange mailbox

Click Next.

Locations fields completed

Click again on Next.

Define search conditions

Click on Submit.

Review search and create

New search created. Click Done.

New search created

In the next step, we will export the PST file.

Step 3. Export Office 365 mailbox to PST file

In the Content search list, click on the name that you created in the previous step.

Select created search in list

You will see that the search status is completed.

Search is complete

Click on Action. In the menu, click on Export results.

Export search results

Select the output options that you like to have. Click Export.

In our example:

  • All items, excluding ones that have unrecognized format, are encrypted, or weren’t indexed for other reasons
  • One PST file for each mailbox.
Export results to PST file

In the final step, we will download the Office 365 PST file.

Step 4. Download Office 365 mailbox PST file

Click on the tab Export. Then, click on the list on the export object.

Select created export in list

Copy the export key by clicking on Copy to clipboard. After that, click on Download results.

Copy export key to clipboard and download results

You will see a warning that you must use Microsoft Edge or Internet Explorer to download search results or reports.

If you use a non-Microsoft browser, you need to install the ClickOnce browser extension. Find the extension on the add-on webpage for that browser.

Warning that you must use Microsoft Edge or Internet Explorer to download search results or reports

Install the Microsoft Office 365 eDiscovery Export Tool.

If the tool doesn’t start, read the Microsoft documentation You can’t start the eDiscovery PST Export Tool.

Install Microsoft Office 365 eDiscovery Export Tool

Paste the export key that you copied. Next, select a location for the PST file. In our example, we will save the export to the directory path C:\PST files. Click Start.

eDiscovery Export Tool

The status will show that the download completed successfully. Click Close.

eDiscovery Export Tool download completed succesfully

Go to the download location path and find the PST file.

Find PST file in download location

That’s it!

Change PST file export size

When you use the eDiscovery Export tool to export the email results of an eDiscovery search, the default size of a PST file that you can export is 10 GB. The 10 GB default file size is a good balance between the optimal amount of content in a single PST and a minimum chance of file corruption.

You can change the default 10 GB PST export file size. On the computer that you run the eDiscovery Export tool to export the results to PST, follow the steps:

1. Close the eDiscovery Export tool if it’s open.

2. Run Registry Editor and create the following registry key:


3. Create a new String value for 20 GB in PST export file size:


4. Do you need another PST file size? Change the String value to the desired maximum size of an export PST file. See the below table for other sample values.

Size in GBSize in bytes
1 GB1073741824
5 GB5368709120
10 GB10737418240
15 GB16106127360
20 GB21474836480

Did the export Office 365 mailbox to PST file from Microsoft 365 compliance center work for you?

Keep reading: Find specific SMTP address with PowerShell »


You learned how to export an Office 365 mailbox to PST file. There are four steps involved. First, assign eDiscovery permissions to the administrator account. Second, create a new content search with the administrator account. The third step is to export the results. The last step is to download the PST file to the computer.

Another way to export Office 365 mailboxes is to give yourself full access right to the mailbox. Then, when you start Outlook, you will see the mailbox in the left panel. After that, you can export to PST file from Outlook. That will get the job done, but the steps in this article are more convenient.

Did you enjoy this article? You may also like Export distribution group members to CSV with PowerShell. Don’t forget to follow us and share this article.



ALI TAJRAN is a passionate IT Architect, IT Consultant, and Microsoft Certified Trainer. He started Information Technology at a very young age, and his goal is to teach and inspire others. Read more »

This Post Has 5 Comments

  1. I love your work Ali and your attention to detail is excellent. I always recommend your page to my colleagues!!

  2. Hi Ali, Thank you for post. i wanna ask you about powershell.. How can i start export pst by powershell.. i want to automatize this process.

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