How to Import PST File to Exchange Online Mailbox? All Tested Methods

Prerequisites: Assign Mailbox Import Export Role & Admin Access

• The Exchange Mailbox Import Export Tool is not assigned by default. Grant it to yourself or an administrative service account by On-primses 2013.
• You must have full Access to the user mailbox to import PST in Exchange Mailbox.
• If using on-premises New-MailboxImportRequest cmdlet, store PST files on UNIC -accessible file share. Grant the Exchange Trusted system(or your service account) Read permissions on that share.
• For Exchange Online Network Upload, install AzCopy on your workstation and must be clear that you can connect AzureStorage via SAS URL generated in Microsoft Preview(formerly Security and Compliance) portal.

Overview of PST Files and Exchange Mailbox Types (Primary vs Archive)

A PST file is an Outlook data file used to store emails, calendar items, contacts, and more. Many organizations still use PST files to hold legacy or backed up emails. However, keeping data in PST files is not ideal for long-term storage, compliance or accessibility, which is why importing them into Exchange mailboxes is recommended.

Types of Exchange Mailboxes

Primary Mailbox: Its user main mailbox uses it when PST data is current and active.
Archive Mailbox: It is also known as In-place archive mailbox. Ideal to archive older emails and older files. This keeps the primary mailbox maintained and helps to navigate specific data easily.

Method 1: Import PST to Exchange Mailbox Using PowerShell (New‑MailboxImportRequest)

If you are running On-premises Exchange Server 2010 SPI and above version then the most direct way to import PST to Exchange Server is using PowerShell. This approach is reliable and offers you complete control over the import process.

Syntax and Common Parameters

Basic example: New-MailboxImportRequest -Mailbox “username” -FilePath “\\FileServer\PSTs\user1.pst”

Common Used Parameters

• -Mailbox: Specifies the target mailbox(username or email address).
• -File Path: The UNC Path to PST file(must be accessible by Exchange Server).
• -TargetRootFolder: Optional – defines where to import PST data inside the mailbox.
• -Include Folder – Optional allows importing only specific folders(e.g., Inbox/ Sent Items).
• -IsArchive: Optional-use this to import directly into Archive mailbox instead of primary.

Running On-Premises vs Exchange Online

• On-Premises Exchange(2010 SP1-2019): New-MailboxImportRequest is fully supported and widely used.
• Exchange Online(Microsoft 365): This cmdlet is not available in the cloud. You must use Microsoft Preview Compliance Center with PowerShell+AzCopy instead.

Strengths and Limitations

• Fast and direct import for on-premises environments.
• Full control through scripting.
• Support folder filtering and archive mailbox targeting.
• No-third party tools required.

Method 2: Network Upload Method to Import PST to Exchange Online Mailbox

If you’re working in Microsoft 365(Exchange Online), you can’t use the traditional New Mailbox Import Request method. So, you need to use Microsoft provides Network Upload via Microsoft Preview Compliance Portal. This method lets you upload PST files to Azure Storage, map them to mailboxes and start on import jobs all without requiring Outlook.

Part1. Generating SAS URL in Microsoft Purview Portal

1. Sign in to Microsoft Purview Compliance Portal.
2. Navigate to Data Lifecycle Management then tap on Import.
3. Click on New Import Job and choose to upload your data and follow the procedure.
4. The portal will generate a SAS URL(Secure Access Signature) this URL allows you to upload PST files directly to Microsoft Azure Storage.

Part2. Uploading PST files using AzCopy or Azure Storage Explorer

1. Download and install AZ Copy(command-line-tool) from the official Microsoft site.
2. Use SAS URL to upload your PST files: AzCopy.exe copy “C:\PSTs\user1.pst” “https://?”-overwrite=prompt.

Part 3. Creating and Validating CSV Mapping File

1. Workload: FilePath, Name, Mailbox, IsArchive
2. Exchange:user1.pst, user1, user1@domain.com, FALSE.
3. FilePath: The name of the uploaded PST file.
4. Mailbox: The destination mailbox in Exchange Online.
5. IsArchive: Set to TRUE if you want to import the archive mailbox.

Part 4. Creating and Starting the Import JoB

1. Return to the Purview Portal and find your Job and submit the CSV mapping file.
2. Once validated, Microsoft starts the import process.
3. You’ll be notified in the portal when the JOB is created and processing begins.

Part 5. Monitor and Verify Job Status

1. In the import section of the portal, you can monitor job status.
2. It shows whether each PST file has successfully been imported or if any errors occurred.
3. You can also download logs for more detail.

Part 6. Filtering Options and Support Limits

1. Data filters must be included in CSV(via FilterCriteria through).
2. You can exclude large folders like Deleted Items or Junk.

Method 3: Drive Shipping Method for Large Volumes

Part 1. Preparing BitLocker‑Encrypted Hard Drive with WAImportExport.exe

1. Use Microsoft BitLocker to encrypt physical hard drives(USB 3.0 preferred).
2. Copy all PST content in the hard drive, maintain a clear folder structure.
3. Verify PST name matches the expected mapping format for later days.

Part 2. Shipping to Microsoft Data Center

1. Encrypt the drive with BitLocker.
2. Generate a drive journal file that logs what whats

Part 3. Creating Mapping, Submitting Job, and Cost Considerations

• Once the files are uploaded, create a CSV mapping file(same format as network upload) and submit it through Import Wizard in Microsoft Purview Compliance Portal.

Part 4. Cost and Considerations

1. Microsoft charges a flat fee per drive(currently around @2 USD per GB import).
2. The shipping process and manually importing may take several days.
3. You’re responsible for tracking the drive and ensuring it’s properly encrypted and labeled.

Notable Attributes of Recommended Software

• This software offers a simple initiative interface to make it a reliable tool to operate by all professional and individual users.
• You can also convert PST to PDF, EML, MBOX, MSG, and many more saving options.
• With this wizard you can also use filter options such as create PST year wise, from, to, subject. Exclude folders, organizer, root folder, exclude empty folder, mails, calendars, contacts, create Exception log and more.
• This wizard can easily import individual or batch Outlook files without facing any limitations.
• It supports Auto detect feature to easily locate Outlook files and also offers let me select features to browse from any custom location.
• With this tool, you can also import PST to Gmail, Thunderbird, Yahoo and all IMAP Supported email servers.

Ending Remarks

In this guide, we have shared all possible solutions to import PST to Exchange Server by manually and using Alternative Approach. As a manual approach requires deep technical expertise and is not reliable to perform by beginners and those users want to import in bulk data. So, we recommend you to choose Expert Verified Method as it is specially designed for managing bulk Outlook data and also specially known for maintaining results as it is widely used for forensic purposes.