If you are looking for PST to Office 365 migration software capable of easily migrating large PST files to O365, you can use the MailsDaddy PST to Office 365 Migration Tool. The tool migrates your large PST files to Office 365 in just a few clicks, while preserving email attachments and the original folder structure. It safely imports PST emails, contacts, calendars, tasks, attachments, notes, and journals to Office 365 without any data loss. https://www.mailsdaddy.com/pst-to-office-365-migration-tool/