I can provide a step-by-step guide for or suggest the best third-party tools for bulk migration.
Free accounts offer 15GB shared across all Google services. download onedrive gmail
"Save Gmail attachments to OneDrive" on the Power Automate website. Connect your Gmail and OneDrive accounts. I can provide a step-by-step guide for or
Microsoft offers a "template" that automatically saves every Gmail attachment you receive into a specific OneDrive folder. download onedrive gmail