How to Import PST to Outlook 365? Complete Guide

Rollins Duke
Published: September 8th, 2025 • 11 Min Read

Hello Readers, As most of the organizations and individuals looking for the solution to import PST to Outlook 365 Web due to Microsoft Cloud ecosystem. A PST(Personal Storage Table) contains emails, contacts, calendars, tasks, journals and other Outlook data stored on a computer. Outlook 365, on the other hand, stores mailbox data in the cloud for easy access, collaboration and security.

As we all know, Microsoft Outlook is an email client that already has several built-in features that allow its users to save their data in the PST format. Many Outlook users also use Microsoft Office 365. Often, when users want to open PST files without Outlook in Microsoft 365, they don’t find a viable solution.

In this article, we will demonstrate how to open PST files in Office 365 using both manual and professional solutions. Additionally, complete and thorough information about both PST files and Office 365.

Users generally import PST file in outlook 365 with the intention of centralizing all of their sensitive information and communication and to make sure they have an easy way to access the PST files anytime, anywhere with top level security and features.

PST File: PST is a Microsoft Outlook application file extension. This application allows users to access multiple account items configured to this application for each user through a private data file. Whenever a new item appears, it will always save that data in the format of a PST folder.

Office 365: It is webmail any new items will be saved to a database in Microsoft 365 and can only be accessed over the Internet via a browser.

Why Import PST to Office 365 Webmail Crucial?

To avoid loss of crucial Outlook data when switching to Microsoft 365.
Once imported, data is visible across all devices through Outlook app and web client.
Microsoft 365 offers retention policies, eDiscovery and data loss prevention features to keep secure PST files.
IT Admins can monitor, manage and backup mailbox data when dealing with scattered PST files.

Manual Methods to Open PST Files in Office 365

Users need to configure both Outlook and Office 365 accounts, which must be an IMAP configuration, if they are not aware of the procedure then just open the application and hit the File tab and choose the Add Account option and enter the login credentials of Office 365. After this, follow the steps mentioned below:

Steps to Open PST File in Microsoft 365

Launch the tool on your system. On the taskbar, click the File tab, then Open & Export, and then Import/Export.
In the Import and Export Wizard, select Import from another program or file. Click Next to continue and open the PST file in Office 365.
Select Outlook Data File (.PST) in the Import a File dialog box. Click Next to continue the process
Click the Browse button in the Open Outlook Data File dialog box to locate the PST file. After that, select the PST file and click Open.
Finally, select the Do not insert duplicates option and click Next to continue the process.

As a result, it is a lengthy process. Not only that, the Outlook email client must be installed properly on users’ computers. The chances of data loss are also high with this method. Moreover, as this process includes a lot of technicalities, non-technical users will not be able to use this method easily.

Recommended: 4 Techniques to Import PST to Shared Mailbox Office 365

Import PST File in Outlook 365 – Limitations Explained

The traditional techniques are unknowingly very slow especially for PST files that are large in size. Also, the PST files with the consumption of gigabytes can take up to hours to complete the process, resulting in the Outlook application running unresponsive and stagnant.
Another drawback of opting for manual methods is the inability to process numerous PST files all at once, making the methods inefficient for professionals and organizations handling large PST files to import PST file in office 365.
Manual methods higher the risk of identifying the same PST files being imported multiple times which further can form duplicate emails in the user’s mailbox, leading confusion.
Users tend to experience several disruptions such as power outages, lost connections, system failures and errors and the list goes on, requiring the them to restart the whole process .
Utilizing manual methods to import PST file to Office 365 webmail does not guarantee of preserving the folder hierarchy of the information contained in an email like sender/receiver details, attachments, Bcc, Cc, etc.
For IT Admins or organizations managing multiple users, manually import isn’t possible.

Professional Solution to Open PST File in Microsoft 365

With the rapid rise of email platforms such as Microsoft Outlook 365, Gmail, Yahoo, Thunderbird, etc., a widely known challenge hangs on both enterprises and individuals to open PST file in office 365. While manual techniques exist, there are times when they prove to be inefficient due to numerous reasons like PST files of large size, risk of errors, less features for smooth process.

In order to tackle such situations, the BitRecover PST to Office 365 Migration Tool is a professional application. Through this application, users can directly convert PST files in Office 365 webmail. With the help of this application, users can open selective folders from PST files to Microsoft 365 webmail user accounts.

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Step-by-Step to Open PST File in Office 365

Firstly, install and launch the software on your system. Select PST files from your computer as a tool that provides dual options to add mailboxes.
Next, select the Convert configured Outlook mailbox data radio button.
Now, choose selective folders from the PST file to upload.
Afterward, select Office 365 as the save format to open the PST file in Office 365 mailbox.
Enter Office 365 account login credentials to continue the migration process
Selecting this option will enable you to perform Mailbox Mapping, i.e., Upload Different PST to Different Office 365 User Accounts
If you are Office 365 Admin, you can map every data file with desired Users. This will help you to open different PST files in different Microsoft Office 365 Users
Finally, log in to your Office 365 webmail & view inserted PST files in your Microsoft Office 365 account.

Benefits to Open PST File in Outlook 365

A certified software tool like this one is distinctively engineered to handle PST files regardless of their size without freezing or crashing. Not only that, the robust tool also has a built-in feature to recover damaged and corrupted files within minutes.
One of the prime reasons behind this user-friendly tool consists of keeping both technical and non-technical users in consideration to operate on it without requiring any complex knowledge of Exchange.
Contrasting to manual techniques needing email client to function properly, this software is standalone. Meaning, users do not need to have Outlook on their system to open PST file in Outlook 365 which is beneficial for orphaned files or users without a valid Outlook License.
Users can easily import PST file in Office 365 in its entirety, involving contacts, tasks, emails, calendars, journals, and notes. Along with that, the tool saves the resultant files to different locations like shared mailbox, primary mailbox, in-place archive, offering utmost flexibility while managing essential data. It is one of the best solutions is to open Outlook calendar to Office 365 online cloud accounts.

How to Import PST to Office 365 Network Upload(AzCopy)?

Uploading PST files over the network to Microsoft’s cloud storage, then importing them into user mailboxes. The Network Upload uses Azure AzCopy, a command line tool designed to transfer PST files to Microsoft Azure storage. Once uploaded, Admin maps PSTs to mailboxes and starts importing through Microsoft Purview(Security and Compliance Center).

Go to Microsoft Purview(Compliance Portal).
Create a New Import Job and generate a Shared Access Generator(SAS) URL.
Download and install AzCopy Tool to your system.
Use AzCopy Command line to transfer PST files to Azure Storage Location defined by your SAS URL.
Example Command: Azcopy.exe/Source:C:\PST files/Dest: |V:|Y
Ensure all files are successfully uploaded.
In the Microsoft Compliance Center, verify the PST files in your Azure Container.
This helps to confirm file integrity before mapping.
Prepare a CSV file for the correct mailbox in Office 365.
Required column: Workload, FilePath, Name, Mailbox, IsArchive, TargetRootFolder.
Upload the mapped file in Import Job Wizard.
Microsoft Validates the file and prepares data for analysis.
Apply filter to exclude necessary emails as per date range, folder type or item class).
Start the Import Job and monitor the progress and wait until status shows Import Complete.

Drive Shipping Process: Step by Step

Copy All PST files into Physical Hard Drive and lock it for security purposes. It is crucial before importing it.
Once the drive is ready, ship it into Microsoft. Their team uploads the PST files to Azure Storage on your behalf. After upload, the data is available for mapping to the right Outlook 365 mailboxes.
Create a CSV mapping file that links each PST file to the correct user mailbox in Outlook 365. Upload the mapping file in the Microsoft Purview Portal and start the import job.

Initial Setup & Admin Permissions for “import pst to outlook 365”

Before you run the import job, the right admin processes must be set up in the Microsoft 365 environment. Without these roles, you won’t be able to upload or assign PST files to mailboxes.
Assigning Mailbox Import Export and Mail Recipients roles
Go to Microsoft 365 Admin Center for the Security and Compliance Center and assign the mailbox Import/Export role. You’ll also need the Mail Recipients role to manage and assign mailboxes for PST Import.
The person handling the import should be reliable for Global Administrator or have equivalent privileges. At minimum, ensure the account has rights to create Jobs, manage security groups and access user mailboxes for importing PST files into Outlook 365.

How to Import Outlook PST to Office 365?

When you use the network upload method to import Outlook PST to Office 365 the main tool is AzureCopy. This command-line moves PST files from your system into Microsoft’s Azure Storage.

Knowing the right syntax and tips make the smoother process:

/Source – the local folder where PST files are stored.
/Dest – the SAS URL you copied from the Compliance Center.
/V – Creates a log file to track methods.
/Y – overwrite files if needed.
Use /S to upload files recursively.
File Size Recommendation and Handling Large PST Files
PST files larger than 20 GB will take time to upload.
Consider Splitting PST files into smaller ones for faster import.
Avoid network connectivity by importing smaller size PST files.

Mapping File: How to Create and Use IT Effectively

After uploading PST files, you need mapping CSV files that update Microsoft 365 to which PST belongs to which mailbox. Without this, the system won’t know where the data is:
Workload – Always set to Exchange.

FilePath – Path of the PST file in Azure Storage.
Mailbox – User’s Primary SMTP Address.
IsArchive – Set True if importing into Archive Mailbox.
TargetRootFolder – Choose the folder where you want to import data.

Common Mapping Pitfalls to Avoid

Incorrect Mailbox Address – causing mapping errors.
Wrong File Paths – PST won’t be found.
Forgetting to Set IsArchive when importing into Archive mailboxes.
Leaving TargetRootFolder blank if you want data in a specific folder.

Filtering Data During Import

You don’t always need every item of the PST file. Microsoft lets you filter data before import:

Filter By Age, Folder and Message Types
Exclude Items Older than Specific Date(e.g., only keep last 3 years).
Filter by Folder Types(Inbox, Sent Items).
Limit by Message Class(e.g., exclude calendar items).

Compliance and Retention Considerations

Filters help reduce storage use and keep imports relevant,
Be careful, deleting or skipping older data may affect legal/compliance needs.
Always check company retention policies before applying filters.

Monitoring and Finalizing the Import Job

Analysis – Microsoft scans the upload PST file.
Ready – Import Job is prepared to start.
Import in Progress – Data importing in mailboxes.
Complete – Process done now you can access your PST file in Outlook 365.
Complete – Job finished and data is available in Outlook 365.

To Conclude

In this article, we have discussed how to open PST files in Office 365. Many users are facing issues in completing this process. Here, they will find both manual and professional techniques to accomplish this task. The professional method to open PST files in Microsoft Outlook 365 is more safe and more effective than the manual method. The Demo version of this software is also available in which users can save up to 25 files for free.