If you are looking for the best tool to import PST files to Office 365 I suggest Softaken PST to Office 365 Importer Software. I used it recently and found it very simple and reliable for transferring Outlook PST emails, contacts, calendars and attachments directly to Office 365 accounts. The software keeps the original folder structure and data formatting safe during the migration process. It also supports large PST files without causing any data loss. The interface is user-friendly so non-technical users can handle it easily. It saves time and makes the whole migration process smooth and hassle-free.