Regex Email Validation - test@tes_t.com

Question

I have a regex (^[\\w!#$%&\'+-/=?^_{|}~]+(\\.[\\w!#$%&\'*+\\-/=?\\^_{|}~]+)@((([-\\w]+.)+[a-zA-Z]{2,4})|(([0-9]{1,3}.){3}[0-9]{1,3}))\\z) which