That’s…a good portion of the free email providers on the planet. Even if companies are using this list as a filter for signups, it’s only going to be for a limited time.

Companies want new accounts. They don’t mind very much if those accounts are fake - big numbers get investor attention. It only takes a handful of support cases with “I tried to register but it says my email address isn’t allowed” before the C-suite makes it clear to IT that this filter is no longer in sync with the corporate strategy.