title: Laravel sending each e-mail multiple times
body: <p>When a certain event is fired, my Laravel based app has to send exactly one transactional email to each user in a mailing list.</p>
  
  <p>Here is the loop code:</p>
  
  <pre class="lang-php prettyprint-override"><code>$users = User::where('notifiable', 1)-&gt;get();
  
  foreach($users as $user) {
  
      $info = [
          'email' =&gt; $user-&gt;email,
          'name'  =&gt; $user-&gt;name
      ];
  
      $data = [
          'message'   =&gt; 'Sample text'
      ];
  
      Mail::send(['emails.html.notification', 'emails.text.notification',], $data, function($message) use ($info) {
          $message
              -&gt;to($info['email'], $info['name'])
              -&gt;subject('example')
              -&gt;from('admin@example.com','Example');
      });
  
  }
  </code></pre>
  
  <p>Unfortunately, several users are receiving the same mail multiple times.
  I can't figure out what's happening:</p>
  
  <ul>
  <li>When redirecting the emails to log, I see exactly one mail for each user as expected;</li>
  <li>Every other events trigger emails to be sent to a single user. However, no one has received multiple emails from these events.</li>
  </ul>
  
  <p>The app is using Sendinblue as an external SMTP service.
  Some hints I got:</p>
  
  <ul>
  <li>The hourly mail quota was very low -> the email were received 3 times (and the queue on Sendinblue was immediately filled)</li>
  <li>The hourly mail quota was raised 10x -> no more queues on Sendinblue, but now users are receiving the same email up to 7 times!</li>
  </ul>