Migrate PST files to Microsoft Office 365

Hi @Sarah.brag ，

If you only need to cope with a small number of users' PST files, exporting/importing the PST files using the Outlook desktop client could be an option:

• Export or backup email, contacts, and calendar to an Outlook .pst file
• Import email, contacts, and calendar from an Outlook .pst file

Otherwise, although I can understand that you are looking for other alternatives which is free and doesn't involve Azcopy.exe, but for the sake of reliability, personally I'd still recommended using either of the officially offered ways to quickly bulk-import PST files to Exchange Online mailboxes in your organization. You can go through the following document to learn more about both method and choose a compromised one based on your scenario:
Learn about importing your organization's PST files

• Network upload - Upload the PST files over the network to a temporary Azure Storage location in the Microsoft cloud. Then you use the Microsoft 365 Import service to import the PST data to mailboxes in your organization.
• Drive shipping - Copy the PST files to a BitLocker-encrypted hard drive and then physically ship the drive to Microsoft. When Microsoft receives the hard drive, data center personnel upload the data to a temporary Azure Storage location in the Microsoft cloud. Then you use the Microsoft 365 Import service to import the data to mailboxes in your organization.

Drive shipping is simpler, but it's not free. The cost to use drive shipping to import PST files to Microsoft 365 mailboxes is $2 USD per GB of data, see this link for information about pricing.

Network upload is free, but as you may have already known, the AzCopy.exe tool is used to upload and store your PST files. If you are not sure about the whole procedure, you can refer to the step-by-step instructions in the article below:

Use network upload to import your organization's PST files to Microsoft 365

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