MailsDaddy Office 365 to Office 365 Migration tool is the best GUI tool to export Tenant mailboxes from source to destination. The application has multiple features and conversion options by which users can also export Office 365 items to PST, Live Exchange, EML, etc. It comes with the trail edition that exports up to 50 items from each folder. Read more: https://www.mailsdaddy.com/office-365-to-office-365-migration/