[absove]

I've never used glassdoor myself, but don't you need to use your company email while leaving the review to prove you actually work there, so leaving an anonymous review isn't even possible? Why would anybody use glassdoor if that's the case?

[synicalx]

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.