Importing a PST file into Microsoft 365 without Outlook is possible using a dedicated migration tool. This approach can help users move older mailbox data into their Microsoft 365 accounts without opening Outlook. Before starting, identify the PST files you want to transfer and decide whether the data should go into a primary mailbox, public folder, or archive folder.

For this task, Aryson PST to Office 365 Migration allows users to load single or multiple PST files, preview mailbox folders, and select a destination in Microsoft 365. It also supports importing emails, contacts, calendars, tasks, and notes without requiring Outlook installation. This can be useful for individuals and IT teams managing mailbox migration.

When you need to import PST file to Microsoft 365, additional options include date filtering, duplicate email removal, and custom folder naming. The software also supports folder hierarchy preservation during migration. After importing, review the destination mailbox to verify that the required folders and messages are available.