Give permissions to all users from specific domain

I would like to have the option to add a domain with attributes. So I give the domain @searchie.io for example rights on the hub x. All users that have the domain @searchie.io and try to signup will receive automatic a welcome mail as there company paid for the training/membership. This speeds up the process if you have companies with over 500 users. where everybody has permissions to view a course. If after x time I would remove the domain it should no longer give access to any users of that specific domain for that hub. A attribute could be self signedup and paid or company paid. which makes it possible to leave self paid users in the hub.