Office 365 (Microsoft 365), a cloud-based service by Microsoft, comes with enhanced security features, limitless accessibility, extended mailboxes, pay-as-you-go subscription model, real-time collaborative tools, and much more. Due to these and many other benefits, many businesses and organizations are moving from on-premises or desktop-based email clients (Outlook) to Office 365. If you are also moving to Office 365 and looking for ways to migrate your Outlook emails to Office 365 mailbox, then you are at the right place. Here, we will discuss different ways to migrate Outlook emails to Office 365 mailbox.

Ways to Migrate Outlook Emails to Microsoft 365 Mailbox

Below are some manual methods and professional approaches to migrate Outlook emails to Office 365 mailbox.

Method 1: Migrate Emails (PST) using Import Export Wizard in Outlook

You can use Outlook options (Import Export Wizard) to migrate Outlook emails (PST file) to Microsoft 365 (Office 365). To migrate PST file to Microsoft 365 mailbox using Import Export Wizard, you need to first configure Microsoft 365 account in Outlook. Then, you can use the Import/Export wizard to import the PST file. Follow the below-mentioned steps:

  • Open Outlook and click File.
  • Click Open & Export and then select Import & Export.
Open & Export
  • Select the Import from another program option and click Next.
    Import from another program
  • Select Outlook Data File (.pst) and click Next.
select Outlook Data File
  • Browse for the desired Outlook file, select it, and click Next.
Browse Outlook file
  • Select options according to your preference to manage the duplicates within the PST file and click Next.
set option
  • Choose the Import items into the same folder in option and select the Microsoft 365 mailbox. Then, click Finish.

Limitations of this method:

  • Does not work for large-sized PST files.
  • Can migrate a maximum of 500,000 emails from Outlook to Microsoft 365.
  • Capable of migrating only one mailbox at a time.
  • Configuration of Microsoft 365 in Outlook is mandatory.
  • No guarantee of complete data migration as some data can be missing.
  • PST import reports are not available.

Also Read: What is the difference between Microsoft 365 and Office 365?

Method 2: Network Upload Method

It is a great way to import PST files into Microsoft 365 account. However, the user account you’re using to import PST files must have the Import Export and Mail Recipients roles. Follow the below-mentioned steps to import PST files into Office 365 using network upload method:

  • Login to the Microsoft 365 Exchange Admin Center (EAC) and click Roles > Admin Roles. Then, click Import export.
assign import export role to the user
  • Under the Assigned tab, click Add and choose the user you want to assign the role of importing the PST file. After selecting the user, click Add.
choose user to assign import export role
  • Now, create an Import job. For this, visit the Microsoft 365 home page. After logging in, click Data lifecycle management > Import.
  • Click Import PST Files.
select import pst files option
  • Click +New import job and enter the name of the job.
  • Click Next and choose Upload your data option in Select Import Job Type and click Next.
select upload your data option
  • Click Show network upload SAS URL and click Copy to clipboard.
  • Select Download Azure AzCopy to download the tool.
copy sas url download azure azcopy tool
  • Now, extract the downloaded tool on the Desktop and copy the folder of PST files on the Desktop.
  • Open Command Prompt and navigate to the extracted folder on the desktop where azcopy.exe is located with the help of the “cd” command.
  • Upload the PST files to Azure storage using the following command. 

AzCopy copy “source location of pst files” “sas url” –recursive=true

upload folder containing pst files to azure storage

Note: PST files should not be more than 20 GB in size as it can degrade the import process.

  • Once the upload process is completed, use Azure Storage Explorer to verify if the Outlook PST files are uploaded successfully.
  • Launch Azure Storage Explorer after the installation.
  • Select Blob container Shared access signature URL (SAS) and paste the SAS URL you had copied in the Blob container SAS URL: field
upload pst office365 verify pst uploads
  • Click Next > Connect.
  • Under the File Shares tab, you should be able to see the PST folder. You can open the folder to check the PST files.
check verify all pst files in azure storage
  • Now, you need to create a mapping file to map the PST files with user mailboxes. You can use the sample PstImportMappingFile.csv for this purpose.
  • Mention the details and save it as .CSV file.
map pst files with office 365 mailbox csv file
  • Finally, start the PST import process. Go to Microsoft 365 Import data wizard.
  • Check the I’m done uploading my files and I have access to the mapping file options and click Next.
complete the steps to upload import pst files to office 365
  • Click +Select mapping file and then click Validate. Click Next after successful validation. If the validation fails, download the logs to check the error.
upload csv pst mapping file
  • Click Submit and click Done.
complete the steps to upload import pst files to office 365
  • Check the progress report at Information Governance.
  • Once the data is imported, the message will be displayed as Import completed.
pst import to office 365 via upload method complete
  • You can log in to your Microsoft 365 account to access to all your Outlook email items.

Limitations of Network Upload method:

  • Very complex and time-consuming process.
  • Requires Import Export and Mail Recipient roles.
  • Need technical expertise to perform the process successfully.
  • Higher possibilities of PST file corruption.

Method 3: Drive Shipping Method

This is another method to import PST files into Microsoft 365. In this, you need to copy your PST files to a hard drive and ship it to a Microsoft center. Follow the below steps:

Drive Shipping to Import PST to Microsoft 365
  • Download the PST Import tool and secure storage key.
  • Copy the PST files to a hard drive.
  • Create a PST import mapping file and PST import job in Microsoft 365.
  • Ship the hard drive to Microsoft.
  • Go to and sign in using the administrator login credentials.
  • Click Data Lifecycle Management > Import in the left navigation pane.
  • Under the Import tab, click job for the drive shipment and click Enter tracking number.
  • Provide the delivery carrier name, tracking number, and return carrier account number. 
  • Click Save to save the shipping information for import job.
  • Under the Import tab, check the status of your drive shipping import job. Once the status is changed to “Analysis Completed”, you will have the option to import the data contained in the PST files. 
  • Click Data lifecycle management > Microsoft 365 > Import.
  • Click Import to Office 365 and click Next.
  • Click Import data to initiate the import process.
  • When the PST files will be imported successfully to user mailbox, the flyout page will display the status as Completed.

Limitations of Drive Shipping method:

  • Takes a lot of time to import the data to Microsoft 365 as the hard drive shipping takes a significant time and then, the Microsoft team completes the PST import job.
  • Inconvenient method when the PST data needs to be migrated to Microsoft 365 account on an urgent basis.
  • Costs $2 per GB of data.

Method 4: Use a Specialized Microsoft 365 Migration Tool

To overcome the limitations of the above manual methods, you can use a specialized tool such as Stellar Migrator for Outlook to import PST files into Microsoft 365 account. With this Outlook PST to Microsoft 365 migration tool, you can directly select, scan, and upload PST files to Microsoft 365 mailboxes. The best part of this software is that it keeps the original structure and hierarchy of the folders intact after migration. It supports large PST files up to 50 GB each and allows you to migrate mail items even from inaccessible and corrupted Outlook files to Microsoft 365 accounts.


Migrating Outlook PST files to Microsoft 365 account manually is a tedious and cumbersome job. The manual methods can lead to data loss and corruption, interrupted user access, server downtime, and much more. You can avoid these situations and automate your migration with a specialized tool, like Stellar Migrator for Outlook. It allows you to migrate all your PST files to the Microsoft 365 account in a few clicks with complete integrity.  Moreover, you can also add filters to include/exclude deleted or junk folders and choose mail or folders according to your choice during the migration process. All you need with this tool is the PST file and the user credentials of the Microsoft 365 account. 

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William is the primary Writer of the site. He has almost 6 years of experience in the field of technological innovation. William enjoys technology for all aspects, and he's still an ardent DIYer at heart. I've published hundreds of blogs.


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