Restoring historical Outlook data into Microsoft 365 can become complicated when mailbox structure and folder organization must remain unchanged after the process. SysInfo Office 365 Backup & Restore Software offers a practical solution for PST and OST restore to Office 365 by importing Outlook data files directly into Microsoft 365 mailboxes. The software includes a mailbox preview option that allows verification of folders before restoration begins and also removes duplicate emails, contacts, calendars, tasks, and notes to maintain cleaner mailbox data. It preserves mailbox hierarchy throughout the operation and supports selective restoration using date-based filtering. Large Outlook files can also be processed without affecting mailbox integrity. Batch processing helps simplify larger restoration tasks, while secure authentication ensures protected access to Office 365 accounts. Dedicated customer support is available to help resolve technical issues and provide assistance during backup or restoration whenever required.