src/Core/Helper.php
static function validEmail($email, $add_valid_expr = "/^[a-zA-Z0-9]([\w\-\.]?)+/")
    {
        if (filter_var($email, FILTER_VALIDATE_EMAIL)) {

            if ($add_valid_expr) {
                list($valid_string,) = explode('@', $email);
                if (!preg_match($add_valid_expr, $valid_string)) {
                    return false;
                }
            }

            return true;
        }

        return false;
    }
static function validEmail($email, $add_valid_expr = "/^[a-zA-Z0-9]([\w\-\.]?)+/")
    {
        if (filter_var($email, FILTER_VALIDATE_EMAIL)) {

            if ($add_valid_expr) {
                list($valid_string,) = explode('@', $email);
                if (!preg_match($add_valid_expr, $valid_string)) {
                    return false;
                }
            }

            return true;
        }

        return false;
    }
验证电子邮件格式

@param string $email
@param string $add_valid_expr
@return bool