MailsDaddy Office 365 to Office 365 Migration tool is the most affordable program to move one Office 365 account mailbox to another. It manages folder, header, inline images, attachments, meta properties etc. in a Office 365. For the first experience, you may download free demo version and export 50 items from each folder. Read more: https://www.mailsdaddy.com/office-365-to-office-365-migration/