Use the powerful tool i.e. IMAP Backup Tool to perform transfer of IMAP mailbox full to Office 365 account. The software is a desktop based application which supports all edition of Windows such as 10, 8, 7, 8.1, vista etc. The tool just need login details of Office 365 admin account and IMAP Server to move IMAP mailbox full to Office 365. It is compatible to almost all IMAP Servers and has ability to transfer IMAP mailbox full to Office 365 from multiple IMAP servers. To grab more info download the trial version of IMAP to Office 365 account. The trial version allow user to move first 20 emails from IMAP Server to Office 365 account for free of cost.