The best way to migrate Office 365 emails to Gmail is by using the MacSonik Office 365 backup tool for Mac. This is an advanced utility that backup or migrates complete Office 365 mailbox items with high data accuracy. The multiple advanced features help to provide secure migration of Office 365 emails in bulk with high data accuracy. It does not alter any data and folder hierarchy original throughout the migration process. The Office 365 backup tool enables migrating Office 365 emails to other various file formats and email clients efficiently without losing data integrity.