What is the best way to verify that an e-mail address belongs to a business ("work") domain? For example, I don't want [email protected]_ or [email protected]_. But I do want [email protected]_ or [email protected]_.

The first thing that comes to me is to have a rule to exclude gmail.com, outlook.com, yahoo.com, but there are huge amounts of those and it feels stupid to me.

Any thoughts?