To migrate from Google Workspace to Office 365 for 100+ users, using a professional migration tool is the most efficient and manageable approach.

You can use the SysInfo G Suite to Office 365 Migration Tool to handle bulk migration smoothly. First, install the tool and log in with your Google Workspace admin credentials. It allows you to select multiple mailboxes at once or import users in bulk. Then choose what you want to migrate — emails, contacts, calendars, and even Drive data.

Next, log in with your Office 365 admin account and map the users to their respective mailboxes. The tool transfers all selected data while maintaining folder structure, attachments, and data integrity. It also provides options like date filters and duplicate removal, which are useful when migrating large volumes of data.
Read more: https://www.sysinfotools.com/g-suite-to-office365-migration.php