mybb-digest/digest.php

<?php
require_once "vendor/autoload.php";
require_once "activethreads.php";
require_once "email.php";
define("MYBB_ROOT", "../");
define("MYBB_PREFIX", "mybb_");
define("FORUM_ID", 0);// 0 means all forums
$dsn = 'mysql:host=localhost;dbname=mybb;charset=utf8';
$usr = 'root';
$pwd = '123456';

$pdo = new PDO($dsn, $usr, $pwd);
$threads = getLatestActiveThreads(FORUM_ID, 100, true);
$users = $pdo->prepare("SELECT email, username FROM ".MYBB_PREFIX."users
WHERE usergroup = 4
AND isSubscribed = 1");
$users->execute();
$users = $users->fetchAll();
foreach ($users as $user) {
  $email = $user['email'];
  print_email($user['username'], '/unsubscribe', $threads);
}