Here I came with an easy and optimized solution to convert Office 365 mailbox into Gmail on Mac. As a user, I always recommend a professional Mac Office 365 Backup Tool to backup or migrate Office 365 mailbox without any data loss. Office 365 Backup Tool for Mac is a near-perfect and most reliable solution I've ever used. It simply migrates the Office 365 mailbox to a Gmail account without losing folder hierarchy. Moreover, it allows users to export Office 365 emails to various file formats and emails clients in bulk. It has an option to remove duplicate emails from backup and migration.

Know more: https://www.macsonik.com/office365-email-backup/