Please explain me why? They got a permanently free plan, and they allow you to do a catch-all rule (it's an option in the dropdown!) for receiving emails. You

Please explain me why? They got a permanently free plan, and they allow you to do a catch-all rule (it's an option in the dropdown!) for receiving emails. You can then catch all for your domain and redirect to your inbox (or blacklist as needed and such). It's literally a feature they provide.