Free Ways to Import Outlook OST File to Office 365 : Complete Guide

September 29th, 2021 ~ Migration Tips ~ 4 Minutes Reading

Hey, do you have no idea how to import OST file to Office 365?

In this article, I will show you the best and free methods to migrate OST file to Office 365. here you will get the complete guide to upload OST file to Office 365.

Manually import OST file to Office 365 took time and preparation. It also depends on the mailbox’s size. Offline Outlook Data File (.OST) is utilized by numerous POP/IMAP, Exchange server, Microsoft 365, and users. It is mostly linked with all these devices and enables users to access data offline.

Users may still retrieve their emails, calendar, contacts, and tasks even if your internet service is down. They may easily read and write emails, make schedules, and enter data. When they re-establish internet connectivity, their emails and other data remain current.

Exchange Server is a company communication tool that utilizes OST Data files to transmit, receive, and store email communications. Also, it enables users to freeze the OST file, indicating that it has no corresponding inbox account on Exchange and contains unsaved data. But here is a manual method to import OST file to Office 365.

Why Users Migrate OST File to Office 365

Some of the reasons why customers choose to import OST file to Office 365 platform are as follows:

  • There are many advantages to storing your Outlook web mailbox data on a web server such as Office 365.
  • Messages stored in Office 365 are available from anywhere in the world; all that is required is a working internet connection to access them.
  • Office 365 customers may sometimes wish to keep a copy of their Exchange server data in the cloud-based service.
  • Users are searching for a way to import OST file to Office 365 so that they may access them from anywhere at any time.
  • The Exchange may collapse, in which case a trustworthy platform would be required.
  • Prevent the Exchange service outage procedure from being executed.
  • To be able to obtain and interact with information in a secure and dependable setting

How to Import OST File to Outlook

There is no particular and direct way to migrate OST file to outlook. so firstly, we will convert OST file to PST file. After that, we will import the PST file into Office 365.

Step 1: Convert OST File to PST File

  1. Open MS Outlook (click here to visit the official site).
  2. Click on the File tab.
  3. Choose Open & Export options.

    Choose open and export options

  4. And click on the Import/Export option.

    import/export option

  5. Preen on “Export to a File” and choose “Outlook Data File(.pst)” and next.

    Preen on export to a file and choose outlook data file(.pst)

  6. Now select the folders or subfolders to conversion.

    select the folders or subfolders

  7. Now browse the location to save the converted file.

    browse the location to save the converted file

  8. If required, use the built-in tools to delete duplicate emails and press on Next
  9. Also, users may create passwords for your PST file if they want.
  10. At last, press the ok button.

Now successfully OST file will convert into a PST file

Step 2: Import PST file into Office 365

Important Note: There is no way to import a PST file into Office 365. Because Office 365 does not allow users to import any type of file. So, users can not upload and open OST files in office 365. Many websites show you manual methods but that information is incomplete or incorrect. They give users false details. before using those techniques. Verify methods and then take risk of importing OST file into Office 365.

But still, if you want to migrate OST file to Office 365 manually. Then here is the only way to manually import OST file into Office 365. All steps are detailed below (the following techniques are not recommended by us; you are using these techniques at your own risk):

Using Drive Shipping

Using Drive Shipping, you may import your (OST) file into Office 365. To upload the PST files to Office 365, it is necessary to transfer the PST files to the hard disc drive. Microsoft is among the highest-rated product-provider businesses in the world, and one of its features is the ability to import data from a disc drive into Microsoft 365. So, deliver this hard drive or pen drive to Microsoft’s head office to upload OST file to Office 365.


In conclusion, we have described above how to import OST file into Office 365 using the manual technique. The manual method is not as simple as it seems as it has some restrictions and limitations such as it takes time and lengthy process, carries the risk of data loss, and users cannot directly migrate OST file to Office 365 using manual methods can do. In addition, the above-mentioned manual techniques require days and some costs. So, use a third-party tool to avoid these problems.