Back of emails under OVH, how to no loose everything while migrating to Gsuite...?

Hi all!

I need to migrate to Gsuite for emails, and a friend of mine who did this recently lost ALL of her emails 🥲

The problem is that there is no way to talk to a human being at OVH and I have tried to make back ups on OVH Web App which does not support it, and from Apple Mail, which doesn't seem to work either...