Web app allows you to instantly verify the validity of any corporate email address. Simply enter the email you want to check and in a matter of seconds the app will return whether the one submitted is a valid email address or not.
100% free.
My comment: I have tested quite a few email addresses and Email Verifier had always the right answer, independently of where my contacts where based. Simple and effective.
Try it out now: https://www.prospectking.io/email-verifier/