If you are looking for a tool to import OST files into Office 365, take the help of MailsDaddy OST to Office 365 Migration Tool.
Using this software users can import single or multiple OST files into Office 365 single or multiple accounts at a time.
It is helpful to display the preview of the overall OST file database before migration into Exchange online account.
Here users can transfer OST fils into Office 365 Primary and In-Place Archive mailboxes without hassle.
To know more, visit here:
https://www.linkedin.com/services/products/mailsdaddy-ost-to-office-365-migration-tool/