I think you have the option of saying that you're a former employee, and in that case you only need to validate an address not one tied to a specific domain. I

I think you have the option of saying that you're a former employee, and in that case you only need to validate an address not one tied to a specific domain. In any case the idea of a company email is a little hard to define from the perspective of a 3rd party that deals with millions of companies; different TLD's, domains, sub domains etc make it very hard to nail down exactly which pattern is the definition of any given companies real email addresses.