Mail::bcc(MailList::where('dl', 'PendingBulletins')->pluck('email'))->send(new PendingBulletins($subject, $bulletins));

$recipients = MailList::where('dl', 'PendingBulletins')->pluck('email');

foreach ($recipients as $email) {
  Mail::bcc($email)->send(new PendingBulletins($subject, $bulletins));
}