You so realise there's no way to ensure an email address is real and "valid"?
An address entered might be correct according to some rules for some email system but invalid for another.
It might be valid for some system but not exist.
It might be valid and exist but not be reachable for whatever reason.
It might be valid, exist, and be reachable but configured to not accept incoming messages.
Validator interface is the main entry point to bean validation and it is super interface of Validation and ValidatorFactory classes. The easiest way is to use the static Validation.buildDefaultValidatorFactory() method.