WordPress非插件实现评论回复邮件提醒通知

要想在第一时间知道有人在自己博客留言，然后在第一时间回复留言再第一时间通知邮件者，这就需要WordPress博客拥有邮件通知功能。

评论邮件通知的方法：
1.所有回复都发送邮件通知
登陆博客后台，点击“外观”选项卡下的“编辑”选项进入主题编辑界面，在functions.php文件中的之间添加以下函数即可：

/* comment_mail_notify v1.0 by willin kan. (所有回复都发邮件) */
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'])); //e-mail 发出点, 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") . '] 的留言有了回复';
    $message = '
    <div style=" border:1px solid #d8e3e8; color:#111; padding:0 15px; -moz-border-radius:5px; -webkit-border-radius:5px; -khtml-border-radius:5px;">
      <p>' . trim(get_comment($parent_id)->comment_author) . ', 您好!</p>
      <p>您曾在《' . get_the_title($comment->comment_post_ID) . '》的留言:<br />'
       . trim(get_comment($parent_id)->comment_content) . '</p>
      <p>' . trim($comment->comment_author) . ' 给您的回复:<br />'
       . trim($comment->comment_content) . '<br /></p>
      <p>您可以点击 查看回复完整內容</p>
      <p>欢迎再度光临 ' . get_option('blogname') . '</p>
      <p>(此邮件由系统自动发送，请勿回复.)</p>
    </div>';
    $from = "From: \"" . get_option('blogname') . "\" <$wp_email>";
    $headers = "$from\nContent-Type: text/html; charset=" . get_option('blog_charset') . "\n";
    wp_mail( $to, $subject, $message, $headers );
    //echo 'mail to ', $to, '<br/> ' , $subject, $message; // for testing
  }
}
add_action('comment_post', 'comment_mail_notify');
// -- END ----------------------------------------

2.让访客自己选择是否邮件通知
在functions.php文件中的之间添加以下函数，该函数将会在评论框底部生成要不要收回复通知的选项

/* 开始*/
function comment_mail_notify($comment_id) {
  $admin_notify = '1'; // admin 要不要收回复通知 ( '1'=要 ; '0'=不要 )
  $admin_email = get_bloginfo ('admin_email'); // $admin_email 可改为你指定的 e-mail.
  $comment = get_comment($comment_id);
  $comment_author_email = trim($comment->comment_author_email);
  $parent_id = $comment->comment_parent ? $comment->comment_parent : '';
  global $wpdb;
  if ($wpdb->query("Describe {$wpdb->comments} comment_mail_notify") == '')
    $wpdb->query("ALTER TABLE {$wpdb->comments} ADD COLUMN comment_mail_notify TINYINT NOT NULL DEFAULT 0;");
  if (($comment_author_email != $admin_email && isset($_POST['comment_mail_notify'])) || ($comment_author_email == $admin_email && $admin_notify == '1'))
    $wpdb->query("UPDATE {$wpdb->comments} SET comment_mail_notify='1' WHERE comment_ID='$comment_id'");
  $notify = $parent_id ? get_comment($parent_id)->comment_mail_notify : '0';
  $spam_confirmed = $comment->comment_approved;
  if ($parent_id != '' && $spam_confirmed != 'spam' && $notify == '1') {
    $wp_email = 'no-reply@' . preg_replace('#^www\.#', '', strtolower($_SERVER['SERVER_NAME'])); // e-mail 发出点, 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") . '] 的留言有了回复';
    $message = '
    <div style=" border:1px solid #d8e3e8; color:#111; padding:0 15px; -moz-border-radius:5px; -webkit-border-radius:5px; -khtml-border-radius:5px;">
      <p>' . trim(get_comment($parent_id)->comment_author) . ', 您好!</p>
      <p>您曾在《' . get_the_title($comment->comment_post_ID) . '》的留言:<br />'
       . trim(get_comment($parent_id)->comment_content) . '</p>
      <p>' . trim($comment->comment_author) . ' 给您的回复:<br />'
       . trim($comment->comment_content) . '<br /></p>
      <p>您可以点击查看回复的完整內容</p>
      <p>还要再度光临 ' . get_option('blogname') . '</p>
      <p>(此邮件由系统自动发送，请勿回复.)</p>
    </div>';
    $from = "From: \"" . get_option('blogname') . "\" <$wp_email>";
    $headers = "$from\nContent-Type: text/html; charset=" . get_option('blog_charset') . "\n";
    wp_mail( $to, $subject, $message, $headers );
    //echo 'mail to ', $to, '<br/> ' , $subject, $message; // for testing
  }
}
add_action('comment_post', 'comment_mail_notify');
  
/* 自动加勾选栏 */
function add_checkbox() {
  echo '<input type="checkbox" name="comment_mail_notify" id="comment_mail_notify" value="comment_mail_notify" checked="checked" style="margin-left:20px;" /><span for="comment_mail_notify">有人回复时邮件通知我</span>';
}
add_action('comment_form', 'add_checkbox');

3.让博客管理员决定什么情况下发邮件
在functions.php文件中的之间添加以下函数：

/* comment_mail_notify v1.0 by willin kan. (无勾选栏) */
function comment_mail_notify($comment_id) {
  $admin_email = get_bloginfo ('admin_email'); // $admin_email 可改为你指定的 e-mail.
  $comment = get_comment($comment_id);
  $comment_author_email = trim($comment->comment_author_email);
  $parent_id = $comment->comment_parent ? $comment->comment_parent : '';
  $to = $parent_id ? trim(get_comment($parent_id)->comment_author_email) : '';
  $spam_confirmed = $comment->comment_approved;
  if (($parent_id != '') && ($spam_confirmed != 'spam') && ($to != $admin_email) && ($comment_author_email == $admin_email)) {
    /* 上面的判断式,决定发出邮件的必要条件:
    ($parent_id != '') && ($spam_confirmed != 'spam'): 回复的, 而且不是 spam 才可发, 必需!!
    ($to != $admin_email) : 不发给 admin.
    ($comment_author_email == $admin_email) : 只有 admin 的回复才可发.
    可视个人需修改上面的条件.
    */
    $wp_email = 'no-reply@' . preg_replace('#^www\.#', '', strtolower($_SERVER['SERVER_NAME'])); // e-mail 发出点, no-reply 可改为可用的 e-mail.
    $subject = '您在 [' . get_option("blogname") . '] 的留言有了回复';
    $message = '
    <div style=" border:1px solid #d8e3e8; color:#111; padding:0 15px; -moz-border-radius:5px; -webkit-border-radius:5px; -khtml-border-radius:5px;">
      <p>' . trim(get_comment($parent_id)->comment_author) . ', 您好!</p>
      <p>您曾在《' . get_the_title($comment->comment_post_ID) . '》的留言:<br />'
       . trim(get_comment($parent_id)->comment_content) . '</p>
      <p>' . trim($comment->comment_author) . ' 给您的回复:<br />'
       . trim($comment->comment_content) . '<br /></p>
      <p>您可以点击 查看回复的完整內容</p>
      <p>还要再度光临 ' . get_option('blogname') . '</p>
      <p>(此邮件由系统自动发送，请勿回复.)</p>
    </div>';
    $from = "From: \"" . get_option('blogname') . "\" <$wp_email>";
    $headers = "$from\nContent-Type: text/html; charset=" . get_option('blog_charset') . "\n";
    wp_mail( $to, $subject, $message, $headers );
    //echo 'mail to ', $to, '<br/> ' , $subject, $message; // for testing
  }
}
add_action('comment_post', 'comment_mail_notify');
// -- END ----------------------------------------

根据需要随意选择一种。