When it comes to email validate, wow why. But if you have to validate whether the recipient gets the email. You will have to do this either way. If you still

When it comes to email validate, wow why. But if you have to validate whether the recipient gets the email. You will have to do this either way. If you still want to do more, validate the hostname against dns as that can be quick and compared to a typist is not a performance issue(don't forget idn). If you still want to do more, you are only really left with size checks and a few control characters. https://github.com/beached/validate_email https://github.com/beached/validate_email is about what I think is the most one should validate without sending an email you have to send anyways