//访客评论邮件回复
function comment_mail_notify($comment_id) {
    $comment = get_comment($comment_id);
    $parent_id = $comment->comment_parent ? $comment->comment_parent : '';
    $spam_confirmed = $comment->comment_approved;
    if (($parent_id != '') && ($spam_confirmed != 'spam')) {
    $wp_email = 'no-reply@' . preg_replace('#^www\.#', '', strtolower($_SERVER['SERVER_NAME']));//发件人 e-mail 地址，no-reply 可改为可用的 e-mail
    $to = trim(get_comment($parent_id)->comment_author_email);
    $subject = '您在 [' . get_option("blogname") . '] 的留言有了新的回复';
    $message = '您好！' . trim(get_comment($parent_id)->comment_author) . '，';
    $message .= '您于'. trim(get_comment($parent_id)->comment_date) .  ' ';
    $message .= '在《' . get_the_title($comment->comment_post_ID) . '》发表评论：' . '';
    $message .= ''  . nl2br(get_comment($parent_id)->comment_content) . '';
    $message .= '';
    $message .= '' . trim($comment->comment_author) . '';
    $message .= '于'. trim($comment->comment_date) . ' 给您的回复如下';
    $message .= '' . nl2br($comment->comment_content) . '';
    $message .= '';
    $message .= '您可以点击下方按钮查看回复内容';
    $message .= '查看回复' . "";
    $from = "From: \"" . get_option('blogname') . "\" ";
    $headers = "$from\nContent-Type: text/html; charset=" . get_option('blog_charset') . "\n";
    wp_mail( $to, $subject, $message, $headers );
    }
}
add_action('comment_post', 'comment_mail_notify');