If you are in search of a reliable approach to migrate Office 365 to Gmail then, I would recommend going with the MacSonik Office 365 backup tool for mac. This utility helps to backup complete Office 365 mailboxes like contacts, tasks, notes, and impersonation accounts. It maintains data security and integrity throughout the migration and removes duplicate emails from the process. The Office 365 backup tool offers users to migrate/convert Office 365 emails to PDF, PST, MBOX, Gmail, Thunderbird, Opera Mail, etc. It also provides an interactive interface that makes the task easier for both technical and non-technical users.