How to Migrate OST to Microsoft Office 365?

Puzzled how to migrate OST files to Office 365 easily? You’re not alone, many users face the same issue. OST to Office 365 migration is a tricky process to perform since these files can’t be accessed anywhere apart from their configured Outlook profile. In this blog, we’ll explain the manual method in detail to help you migrate OST files to Office 365. For a quicker alternative, we’ll also go over a professional tool that will simplify the whole OST to Office 365 migration process.

Reasons to Migrate OST to Office 365? 

There can be multiple reasons why users might want to migrate their OST files to Office 365 mailbox. Let’s look at some of the most common reasons below:

Backup: Move OST files to Office 365 mailbox to create backup of important data. This is helpful in case of accidental deletion or system crash.

Archiving: Archive old OST files to Office 365 mailbox to free up space and improve Outlook’s performance.

Centralized storage: Migrating OST to Office 365 stores data at a single location, allowing easier access.

Advanced features: Office 365 offers multiple advanced features and strong security measures that makes it a better choice for users. 

Easy access: Migrating OST files to Office 365 makes them easily accessible by anyone with the necessary permissions.

Better collaboration: By importing data to Office 365, you can easily collaborate with clients and colleagues on different projects. 

Pre-requisites of OST to Office 365 Migration 

A smooth migration requires careful and detailed planning. There are some essential steps you must take beforehand. These steps are: 

Create copies of your data: Store copies of your mailbox data at different locations to prevent data loss if the import process fails.

Take inventory of your data: Go through your data once, and check that you’re migrating only the essential files. Skip all the junk or spam files to avoid mailbox clutter and save space.

Check size of OST files: Check the file size of your OST files before starting the migration. Oversized OST files can slow down the migration process and may even lead to downtime.

Permissions: Verify that your Office 365 account has all the required roles and permissions assigned to perform a successful migration. Also, make sure you have enough storage to store all the migrated data. 

Corrupted file: Check for corruption in OST files before starting the migration process. Corrupt file might severely damage your mailbox data and lead to permanent data loss. 

How to Migrate OST to Office 365?

Manual process to migrate OST to Office 365 is very time-consuming, having multiple steps. Firstly, we convert our OST files to PST format using Outlook’s in-built Import/Export wizard. After that, we upload the PST files using the Microsoft Azure AzCopy tool.

Part 1: Convert OST to PST using Outlook’s Import/Export wizard

There’s no way to directly migrate OST to Office 365, you’ll need to convert OST files to PST first. Follow the steps below to convert OST files using Outlook’s Import/Export wizard:

• Start the Outlook application and click on File > Open & Export.
• Click on Import/Export > Export to a file option and then hit Next.
• Choose Outlook Data File (.pst) as the resultant file type and click on Next.
• Select the source folder to export the data from and click on Next.
• Browse the saving location and apply filters for duplicate items, then finally click on Finish.

Part 2: Import PST to Office 365 using Azure AzCopy tool

Now, we’ll import the converted PST files to Office 365 using the Azure AzCopy tool. The detailed steps to upload the files are given below:

Step 1: Assign roles and permissions

• Sign into Office 365 admin account with the correct administrator credentials.
• Click on Admin from the left panel to open the Microsoft Admin Center.
• Choose Exchange from the Admin centers section. The Exchange admin center will open.
• Click on Roles and from the drop-down, choose Admin roles.
• Scroll down the list and choose Organization Management. A new window will open on your screen.
• Click on the Permissions tab and tick the Mailbox Import Export checkbox. Click on Save.

Now, back in the Organizational management window, go to the Assigned tab and click on Add to assign roles and permissions to the necessary users.

Step 2: Set up a new PST Import Job

• In the Microsoft 365 admin center, now open the Microsoft Purview portal.
• Click on the Solutions tab from the side panel and choose Data Lifecycle Management from the list.
• Choose Import from the side panel and click on the New import job tab.
• Give a name to the newly created PST import job and click on Next.
• Click on Upload your data option and proceed to the next step.
• Click on Show network upload SAS URL and copy it to clipboard. It’ll be useful later-on.
• Click on the given link to download the Azure AzCopy tool to upload PST to Office 365.

Step 3: Upload PST to Azure Storage

• Open the cmdlet command prompt and then go to the location where your azcopy.exe file is saved.
• Type ‘cd’ in front of the azurecopy.exe location and input it in the command prompt.
• Now, open the location where your PST files are saved and copy the file location.
• Paste the PST file location and the SAS URL copied in the previous step, in the following command and run it in the command prompt:
• azcopy.exe copy "" ""
• After the PST file is imported successfully, create a CSV mapping file. This CSV mapping file will be useful in the coming steps.
• Tick these two checkboxes: I’m done uploading my files & I have access to the mapping file and click on Next.
• Upload CSV mapping file created earlier and click on Validate.
• Once the file is successfully validated, click on Next.
• Check the details provided properly and finally click on Submit.
• Regularly check the Import page until the status is displayed as completed.

Step 4: Import PST to Office 365

• Next, check the box for your new import job and select Import to Office 365 option to continue.
• Click on the No, I want to import everything option and move to the next step.
• Verify all the details of import process and click on Submit.
• Once the upload process is completed successfully, Upload to the cloud succeeded message will display on your screen.
• After Microsoft processes the import request, your process will start.
• Check the progress status in the Import section.

Migrate OST to Office 365 safely with Email Migrator

Migrating OST files to Office 365 manually is a tricky process using the Azure AzCopy tool. One must have detailed knowledge of the Microsoft Purview Portal and solid technical expertise. Even a single mistake while attempting the Network Upload method can seriously put your data at risk. Hence, choosing the correct method to import your files is necessary to avoid data loss.

As per our recommendation, using a professional Email migration tool is the best option to complete the entire migration process in few simple steps. Email Migrator handles the transfer of emails and attachments to primary, archive, and shared mailboxes with precision, without the risks of manual methods.

Conclusion

While we've given the details for migrating Outlook OST files to Office 365 via Network Upload, it's important to note this method requires significant time and technical expertise. For most users, especially beginners, a professional email migrator offers a simpler, worry-free alternative. Tools like Email Migrator migrate your emails and other mailbox items to Office 365 without any loss or corruption.