How to Import PST Files into Exchange Online in Microsoft 365

Before starting the import process, you need proper permissions. Navigate to the Exchange Admin Center and assign the Mailbox Import Export role to your administrator account.

Open your browser and go to the Exchange Admin Center. In the left navigation, click Roles, then select Admin roles. Find and click on Organization Management.

Click the Permissions tab, then locate and select the Mailbox Import Export role. Click Save to apply the changes.

Access the Microsoft Purview portal to create your PST import job. This generates the Azure storage location where you'll upload your PST files.

Navigate to the Microsoft Purview portal through your Microsoft 365 Admin Center. In the left menu, expand Information governance and click Import.

Click Import PST Files, then click New import job. Give your job a descriptive name like "Q1-2026-PST-Migration" and click Next.

Select Upload your data and click Next. On the next screen, click Show network upload SAS URL.

Copy the generated SAS URL to a text file. This URL contains your storage account name, container name, and shared access signature token. It looks like this:

https://3c3e5952a2764023ad14984755276b0d.blob.core.windows.net/ingestiondata?sv=2015-04-05&sr=c&si=IngestionSasForAzCopy201601121920498117&sig=Vt5S4hVzlzMcBxuRqkQeGjvHPrt%2BHmS7fbZ8NL%2FgQas%3D

AzCopy is the only officially supported tool for uploading PST files to Microsoft 365. Download and install the latest version for reliable file transfers.

Download AzCopy from the official Microsoft website. For Windows, download the executable and extract it to a folder like C:\AzCopy.

Open Command Prompt as Administrator and navigate to your AzCopy folder:

cd C:\AzCopy

Test AzCopy installation by running:

azcopy --version

You should see version information displayed. The current version as of 2026 is AzCopy v10.x.

Create a dedicated folder for your PST files if you haven't already:

mkdir C:\PST_Files

Copy all your PST files to this location. Ensure file names don't contain special characters or spaces.

Now upload your PST files to the Azure storage location using the SAS URL from step 2. This process transfers your files securely to Microsoft's cloud storage.

Open Command Prompt as Administrator and navigate to your AzCopy directory. Run the following command, replacing the placeholder with your actual SAS URL:

azcopy copy "C:\PST_Files\*" "[YOUR_SAS_URL]" --recursive --log-level=INFO

For example:

azcopy copy "C:\PST_Files\*" "https://3c3e5952a2764023ad14984755276b0d.blob.core.windows.net/ingestiondata?sv=2015-04-05&sr=c&si=IngestionSasForAzCopy201601121920498117&sig=Vt5S4hVzlzMcBxuRqkQeGjvHPrt%2BHmS7fbZ8NL%2FgQas%3D" --recursive --log-level=INFO

The upload progress will display in real-time. Large files may take considerable time depending on your internet connection speed.

Monitor the upload carefully. AzCopy will show transfer statistics and any errors encountered during the process.

Create a CSV mapping file that tells Microsoft 365 which PST files to import into which mailboxes. This file controls the entire import process.

Open a text editor like Notepad and create a new file. The CSV must contain specific columns in the exact order shown below:

Mailbox,IsArchive,TargetRootFolder
john.doe@company.com,FALSE,/
jane.smith@company.com,TRUE,/
mike.johnson@company.com,FALSE,ImportedData

Here's what each column means:

• Mailbox: The primary email address of the target user
• IsArchive: FALSE for primary mailbox, TRUE for archive mailbox
• TargetRootFolder: Destination folder (/ for root, or specify folder name)

Save this file as PST-Import-Mapping.csv in an easily accessible location like your Desktop.

For users without archive mailboxes enabled, you must enable them first:

Connect-ExchangeOnline
Enable-Mailbox -Identity "user@company.com" -Archive

Return to the Microsoft Purview portal to upload your CSV mapping file and validate the import configuration before proceeding.

Go back to your browser tab with the import job still open. Click Browse to select your CSV mapping file, then upload PST-Import-Mapping.csv.

The system automatically validates your mapping file. You'll see a green checkmark next to each valid entry, or red error indicators for any issues.

Common validation errors include:

• Invalid email addresses
• Non-existent mailboxes
• Incorrect CSV formatting
• Missing archive mailboxes when IsArchive=TRUE

If you see errors, download the error report, fix the issues in your CSV file, and re-upload it.

Once validation passes completely, click Next to proceed to the final configuration step.

Review your import job configuration and submit it to Microsoft for processing. This initiates the actual PST data import into Exchange Online mailboxes.

Review the import job summary showing your uploaded PST files and mapping configuration. Verify all details are correct, including file names and target mailboxes.

Click Submit to queue your import job for Microsoft's processing. The job status changes to "Analysis in progress" as Microsoft examines your PST files.

This analysis phase can take several hours to complete, depending on the number and size of your PST files. You cannot force or accelerate this process.

Monitor the job status by refreshing the Import page in the Purview portal. The status will change from "Analysis in progress" to "Analysis completed" when ready.

Once analysis completes, you'll see detailed information about each PST file, including size and estimated import time.

After Microsoft completes the analysis, initiate the actual import of PST data into your Exchange Online mailboxes.

Select your completed import job from the list and click Import to Office 365. This opens the final import configuration dialog.

Choose your import scope:

• "No, I want to import everything" - Imports all data from PST files
• "Import only the last two years of messages" - Filters older content

For most migrations, select "No, I want to import everything" to ensure complete data transfer.

Click Next to review the final settings, then click Submit to start the import process.

Click Done to return to the import jobs list. The status changes to "In progress" as Microsoft imports your data.

The import process includes all mailbox data: emails, calendar items, contacts, tasks, and notes from the PST files.

Once the import completes, verify that all PST data successfully transferred to the target mailboxes and troubleshoot any issues.

Check the import job status in the Purview portal. A successful import shows "Completed" status with detailed statistics for each PST file.

Download the import completion report by clicking on your completed job and selecting Download report. This CSV file contains detailed results for each imported item.

Log into each target mailbox to verify data presence:

• Check email counts match expectations
• Verify calendar appointments imported correctly
• Confirm contacts are present
• Test search functionality for imported content

For archive imports (IsArchive=TRUE), access the archive mailbox through Outlook or Outlook Web App to verify content.

If you specified custom target folders, navigate to those locations to confirm proper data placement.

Common post-import tasks include:

• Updating user permissions on imported folders
• Configuring retention policies for imported data
• Training users on accessing their imported content