How to Upload OST to Office 365 Accounts Professionally? 

Microsoft Exchange is a service used by organizations and collaboration environments for network sharing and internal communication (external too). The shared folders enable connected clients to communicate in real-time basis by direct file sharing. Meanwhile, email communication enables long-term communication for faster - detailed and distant communication. Provision to work offline is also featured by the email server to enable mailbox accessibility despite server unavailability. However, since the emergence of cloud computing, on-premise services have become slightly frail. Therefore, an increase in the ratio of users willing to migrate OST to Office 365 mailbox became evident.

The following blog is a detailed discussion upon the respective migration and why and wherefores associated with it. Read more to know the procedures that make it possible to execute such a conversion.

Open OST File without Exchange

Opening OST file without exchange, especially the origin forest is most likely impossible. It is necessary for opening any file that its respective platform or environment is made available.

Unless the encryption key does not match on both the ends, synchronization between OST and Exchange mailbox cannot take place. Therefore, it is impossible to:

  1. Open an OST file without connectivity to Microsoft Exchange Server.
  2. Open / synchronize OST with a mailbox residing on a different Exchange forest.

Organizations prefer to move OST to Office 365 owing to the universal accessibility it renders to the account holders. Here is a detailed look at the whole scenario of migrating from Exchange offline storage to hosted mailbox.

Manual Workaround vs. Commercial Application

In order to know how to migrate OST file to Office 365

Following are the two ways to carry out the migration of offline Outlook profile to O365:

  1. Manual Workaround
  2. Commercial Application

Manual: The manual procedure is divided into two stages as described below.

Move OST to PST

  1. Log into your Exchange cached profile
  2. Click on New Items, go to More Items and select Outlook Data File to create a personal folder
  3. Select and move items from the offline profile to the newly created personal folder
  4. Close the Outlook Data File and Exit Outlook

Import PST in O365

The two ways to migrate an Outlook Data File into O365 profile:

  1. Azure File Copy: Azure renders a way to upload PST to Office 365 with PowerShell commands. You need to install the file copy module and create a command to upload any or all PST files to be uploaded on network.
  2. Send in Drive: If you want to save yourself from making all the efforts of downloading a tool, creating a command, and executing it, simply go for drive shipping. You can copy the PST file(s) in a hard drive that are to be uploaded on Office 365, secure it with encryption and send it to Microsoft for upload. This method generally demands a lot of time and monetary investment.


  1. OST to PST conversion is not possible manually if the profile is not connected with Exchange Server.
  2. Import procedures meant for uploading PST on Office 365 are excessively lengthy and complicated to be implemented.

Commercial: Download and Install the applications used in combination to migrate OST to Office 365.

OST to Office 365 Converter is designed in such a way that it takes only few moments and moves all your data to OWA. The tool comes up with numerous of inbuilt functionalities that makes easy to perform the data conversion in an efficient manner. The best thing about the software is it directly migrates all the data to Exchange online account. The tool does not require any external utility to perform the data migration.

Noteworthy Features of OST to Office 365 Converter

  1. No Exchange and Outlook connectivity is needed.
  2. Supports all Windows and MS Outlook versions
  3. Offers 2 modes of migration – Selective & Batch
  4. No file size limitation is imposed on the software
  5. Comes up with free demo edition to test the tool
  6. No technical knowledge is required for conversion

The Bottom Line about Migrate OST to Office 365

Office 365 being a cloud account is accessible over a variety of platforms like Windows or Mac. Due to this, most of the time users need to move all their data to cloud-based. In the above discussion, we have discussed the way to migrate OST to Office 365 mailbox in an efficient way.