If you are using an Outlook.com, Exchange Online, or IMAP email account in Outlook, an OST file is created automatically to store mail items. But this OST file cannot be imported directly into Microsoft 365 unlike PST files. In this post, you will learn free methods to import OST files into Microsoft 365. You will also get to know about a reliable OST to PST converter tool that helps you to directly import OST files into Microsoft 365.
Why Import OST to Microsoft 365?
Migrating your offline Exchange mailbox data to a cloud platform like Microsoft 365 offers various advantages such as quick data access, no downtime maintenance, and automatic upgrades. Some of the reasons to move from Exchange Online to Microsoft 365 include:
- Enterprise-grade security of Microsoft 365.
- Need for a reliable platform to avoid frequent exchange crashes.
- Shifting of organization owing to benefits of Microsoft 365.
- Microsoft 365 mailboxes can be opened from any device like iPhones, Android phones, tablets, and more.
- Can be accessed from anywhere, at any time.
- Microsoft 365 is a more convenient and easier-to-use platform than Outlook
Methods to Import OST File to Microsoft 365
Importing an OST file to Microsoft 365 can be challenging because OST files are associated with an Exchange email account and are used for local caching of email data. On the other hand, Microsoft 365 imports data largely through PST (Personal Storage Table) files. Let’s check the methods to import OST files to Microsoft 365:
Method 1: Using Archive Feature
- Step 1: Launch Outlook and go to the File tab from the top menu. In the Info section, select Cleanup Tools option in the list. Select “Archive” from the drop-down menu.
- Step 2: Select all the files and folders that need to be archived. You can also select the files based on their dates under “Archive items older than”.
- Step 3: Set a location for the archive file and click “OK” to convert the OST file to PST.
- Step 4: Check the location where the archived PST file has been saved to confirm the archival of saved items.
Note: The archive method works only if the OST file is accessible. If the OST file is orphaned or corrupted, you will not be able to archive or export emails to PST format. To convert corrupted OST files, you must use a professional OST to PST converter tool (as mentioned in method 3).
Method 2: Convert OST to PST Format
In this method, you need to convert the OST file into a PST file, upload the converted files to Azure storage or ship them to the data center of Microsoft, and lastly, import the PST file into Microsoft 365. However, it is important to note that this method will only work if your Outlook profile is active and accessible in Outlook. If the email is deleted or inaccessible due to any reason, this method will not work. In such a case, you can skip to Method 3.
Phase 1: Convert OST File into PST file
- Step 1: Launch Outlook and go to the File>Open & Export>Import/Export
- Step 2: From the given options, choose “Export to a file” and click “Next”.
- Step 3: Choose “Outlook Data File (.pst)” from the given format options and click “Next”.
- Step 4: Select your mail account or individual mailboxes such as “Inbox”, “Sent Items” to export them. You can choose one item at a time. Click the “Include subfolders” checkbox and click “Next”.
- Step 5: Click “Browse” to select the save location of converted files on your device. Click “Finish”. The OST mailbox items will start exporting to the PST data file.
Phase 2: Upload Converted OST Files to Azure Storage or Ship to Microsoft Data Center
Once all the OST files are converted into PST format, you can upload these files to Azure Blob storage using Azure AzCopy. Drive shipping methods can also be used. You need to copy the converted OST files to an encrypted hard drive and ship that drive to the data center of Microsoft. Microsoft team will upload the PST files to Azure Blob storage on a chargeable ($2/GB) basis.
Phase 3: Import the Converted OST Files into Microsoft 365
When you get the PST files, you need to create a user account on Microsoft 365, assign required licenses, create a CSV mapping file, upload it, assign an Import/Export role, and initiate the import job to start importing the OST files into Microsoft 365 mailboxes. This process can take a few weeks or months to import all mailboxes. Moreover, there is a limitation on importing PST files larger than 20 GB or mail items larger than 35 MB in Microsoft 365.
Method 3: Use a Professional migration tool.
This is the easiest and most direct method to migrate the orphaned OST files to Microsoft 365. Stellar Converter for OST Technician helps you to export all the data of OST files into Microsoft 365 mailboxes without interrupting the original folder structure and hierarchy of the data. The tool also enables you to export OST mailbox data into Microsoft 365 and a live Exchange server. Some of the useful features of the tool include:
- Allows preview of recovered OST data before saving it.
- It allows you to export OST data to multiple file formats such as PST, EML, RTF, HTML, PDF, MSG, etc.
- You can migrate converted OST file to Microsoft 365/ Outlook; Live Exchange
- Allows to convert multiple OST files in the batch process
- Allows filtering of data for precise conversion.
- Provide support to all versions of Microsoft Outlook and Windows.
Conclusion
Microsoft 365 provides cloud-based email services along with many other apps and services, making it a wise decision for businesses. There is no need to worry about upgrades, security, or hardware management. In this post, we have discussed manual and software-based methods for importing OST files into Microsoft 365. While the manual methods are complex and time-consuming, third Party tools are an easy-to-use and convenient method to import the OST files directly into Microsoft 365 by using the software. Stellar Converter for OST Technician ensures to repair and conversion of all the mailboxes from OST file to PST format while maintaining complete data consistency and integrity.
