How to Open PST File in Office 365? Complete Guide

  Rollins Duke
Rollins Duke   
Published: August 14th, 2025 • 7 Min Read

Accessing a PST in Outlook 365 is not a universal process. This method tends to ask to select files of a large size in order to measure the user’s data and their knowledge towards the technicality of the tool. Unlike individuals who are new to technology, organizations and professionals dealing with numerous large PST files require a modern tool to work efficiently.

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.

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

  1. Launch the tool on your system. On the taskbar, click the File tab, then Open & Export, and then Import/Export.
  2. 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
  3. Select Outlook Data File (.PST) in the Import a File dialog box. Click Next to continue the process
  4. 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
  5. 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.

Import PST File in Outlook 365 – Limitations Explained

  • Processing Time: 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.
  • Lack of Flexibility: 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.
  • Probability of Duplication: 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.
  • High Risk of Errors: 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 .
  • Hindrances to Data Integrity: 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.

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.

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

  1. 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.

    tool to Open PST File in Office 365

  2. Next, select the Convert configured Outlook mailbox data radio button

    Browse PST File

  3. Now, choose selective folders from the PST file to upload

    selective folders

  4. Afterward, select Office 365 as the save format to open the PST file in Office 365 mailbox

    Office 365

  5. Enter Office 365 account login credentials to continue the migration process

    login

  6. Selecting this option will enable you to perform Mailbox Mapping, i.e., Upload Different PST to Different Office 365 User Accounts

    Mailbox Mapping

  7. 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
  8. Finally, log in to your Office 365 webmail & view inserted PST files in your Microsoft Office 365 account.

    open PST file in Office 365

Benefits to Open PST File in Outlook 365

  • Deals with Large PST Files: 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.
  • Offers Intuitive GUI: 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.
  • Not Dependent on Outlook: 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.
  • Easy Data Migration: 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.

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.


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