package validator import ( "regexp" "github.com/go-playground/validator/v10" ) func validateEmail(fl validator.FieldLevel) bool { s := fl.Field().String() isEmail, _ := regexp.Match(`^\w([\w\-_+]*(\.[\w\-_+]+)?)*@(\w+[\-.])+\w{2,}$`, []byte(s)) hasValidSize, _ := regexp.Match(`^.{0,64}@.{0,63}$`, []byte(s)) return isEmail && hasValidSize }