[yourcard]

When I go to set up a company page, it asks me to verify my company email at the same domain that I input for the company page. All these companies have the domain listed. Someone who is saying they are an employee of a particular company surely could varify the same way.

[hashtag]

Not all companies issue emails to their employees. Users who are adding old positions may not have access. There are all sorts of headaches the other way around too. You have access to your domain and email because you just created the page but that doesn't mean everyone else will. It's a trade off both ways and there needs to be a better solution than what you're suggesting.