If you are searching for the best and most reliable solution to backup your Office 365 mailbox, you can use the Sysinfo Office 365 Backup Tool. It backup your Office 365 mailbox items like emails, attachments, contacts, calendars, etc. This tool backup Office 365 mailbox data locally into PST, PDF, EML, MBOX, and CSV. It performs Tenant-to-Tenant migration in Office 365 or to G Suite, Office 365, and IMAP. In addition, It includes features like maintaining folder hierarchy and data integrity, eliminating duplicate emails, and a date range filter. It is compatible with all the versions of Windows OS.