Written by Jennifer Walsh. Reviewed for technical accuracy by Shubham Dixit, Independent Expert in Email Forensics and Data File Conversion.
Shubham is an independent external reviewer and not an employee of PCDOTS.
Quick answer. Office 365, now Microsoft 365, gives real free ways to export a mailbox to PST. A single user exports it in Outlook with Import / Export. An admin exports one or many mailboxes through the Microsoft Purview compliance portal’s Content Search. A tool does it in bulk without the portal. Note there is no Export-Mailbox cmdlet in Exchange Online.
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Office 365, Microsoft 365, the same thing
A quick note on names, since the searches use all of them. Office 365 was renamed Microsoft 365, and O365 and M365 are just short forms of the same service. Under the hood the mail lives in Exchange Online. So every one of those terms points at the same job, getting a mailbox out of the cloud and into a PST file on disk.
How you do that depends less on the name and more on who you are. A single user works in Outlook. An admin moving one or many mailboxes uses the compliance portal. Here are both, plus the scripted route and a tool.
Who you are decides the route, both a user and an admin can reach a PST for free.
“The point people trip over is that Exchange Online is not on-premises Exchange, so the old Export-Mailbox cmdlet simply is not there. In the cloud the sanctioned way to get a PST is the compliance side, a Content Search in the Purview portal, then the eDiscovery export, or the same thing scripted with New-ComplianceSearchAction. For a single person their own Outlook does it, and for a batch without eDiscovery rights a tool is reasonable, but no one should go hunting for a cmdlet that does not exist.” Shubham Dixit, Email Forensics reviewer (draft, pending approval)
A single mailbox, in Outlook
If you just want your own mailbox as a PST and you use the Outlook desktop app, this is the free, built-in way, no admin rights needed.
Make sure your Microsoft 365 account is added to Outlook and has synced. Then go to File, Open and Export, Import / Export, choose Export to a file, then Outlook Data File (.pst). Pick the mailbox or the folders you want, choose a destination, and optionally set a password on the PST. Outlook writes the mailbox to a .pst on your computer. It is ideal for one mailbox and leans on Outlook having the whole mailbox downloaded, so very large mailboxes take a while.
One or many, the eDiscovery export
For an admin exporting someone else’s mailbox, or several at once, Microsoft’s own free route is the compliance portal, no per-user Outlook needed. You need the eDiscovery Manager role assigned first.
Open a Content Search. In the Microsoft Purview compliance portal, go to Content search (or eDiscovery), and create a new search.
Scope it to the mailbox. Add the mailbox or mailboxes as locations, add conditions if you only want a date range or certain items, and run the search.
Export to PST. When the search finishes, choose Export results, then download the results with the eDiscovery export tool. It saves a PST for the mailbox, or a set of PSTs for a batch, onto your computer.
The PowerShell route, and a myth
Plenty of people search for a PowerShell way to do this, and there is one, but first the myth. In on-premises Exchange there was an Export-Mailbox, later New-MailboxExportRequest, cmdlet. In Exchange Online there is no such cmdlet, so a script that calls it will simply fail. Cloud PST export runs through the same compliance search as above.
Connect to Security and Compliance PowerShell, create the search with New-ComplianceSearch, start it, then export it with New-ComplianceSearchAction -Export. You still download the finished PST with the export tool. It is the scripted version of the portal steps, handy when you are doing this often or across many mailboxes.
In the cloud there is no Export-Mailbox, the compliance search is the scripted route.
Simple bulk, a tool
The compliance export is free but fiddly, roles to assign, searches to run, an export tool to install. If you would rather skip that, or you do not have eDiscovery rights, a tool signs in to the mailbox and saves it as PST directly. The PCDOTS Email Converter connects to the Microsoft 365 account, shows the mailbox, and exports it to PST, keeping mail, attachments, folders and other items, with filters for date, folder or field so you take only what you need. It runs on Windows, handles several mailboxes in a run, and a free version does the first ten items per folder so you can test it first.
The tool route, for simple bulk without eDiscovery setup.
Here are the steps with the screens.
Step 1. Install and run the software on Windows, then open the menu.
Step 2. Choose Email Account, Add Account, and sign in to your Microsoft 365 mailbox.
Step 3. Open the Export menu and select PST.
Step 4. Choose a destination folder and Save.
For related jobs see our guides to migrate Yahoo mail to Office 365, export Yahoo emails to PST, and import PST to an Exchange server.
The methods compared
Match the route to who you are and how many mailboxes you are exporting.
| Method | Best for | Good to know |
|---|---|---|
| Outlook Import / Export | Your own mailbox, free | Needs Outlook, one at a time |
| Compliance eDiscovery export | Admin, one or many, free | Needs eDiscovery Manager role |
| Email Converter tool | Simple bulk, no portal | Windows, filters the export |
Frequently asked questions
Does Office 365 have a direct export to PST?
Not a single button. A user exports in Outlook, and an admin exports through the Microsoft Purview compliance portal’s Content Search, then downloads the PST with the export tool.
Is there an Export-Mailbox PowerShell cmdlet in Office 365?
No. Export-Mailbox exists only in on-premises Exchange. In Exchange Online you export with New-ComplianceSearchAction -Export in Security and Compliance PowerShell.
How does an admin export another user’s mailbox to PST?
With the eDiscovery Manager role, run a Content Search scoped to that mailbox in the Purview portal, then Export results and download the PST with the export tool.
Can I export several mailboxes to PST at once?
Yes. A Content Search can cover many mailboxes and export a set of PSTs, or a tool can run several mailboxes in one job without the portal.
Do I need Outlook to export my mailbox?
For the Outlook method, yes. The compliance export and a tool both work without any per-user Outlook, so choose those if Outlook is not set up.
Are Office 365 and Microsoft 365 the same for this?
Yes. Office 365 was renamed Microsoft 365, and O365, M365 and Exchange Online all describe the same mailbox you are exporting.
What actually exports a 365 mailbox to PST
Strip it back and it is simple. Your own mailbox, one at a time, comes out through Outlook’s Import and Export. Someone else’s, or a batch of them, comes out through a Content Search in the compliance portal and the eDiscovery export, scripted with New-ComplianceSearchAction if you do it often. A tool covers the case where you want a straightforward bulk export without the portal. And the one thing to carry away, there is no Export-Mailbox in the cloud, so the compliance search, not a missing cmdlet, is what turns an Exchange Online mailbox into a PST.
