title: Laravel 5.5 - Notification channels different queue names?
body: <p>In an event listener, I send a notification to a dog owner like this:</p>
  
  <pre><code>$event-&gt;dogowner-&gt;notify(new DogWasWalkedNotification);
  </code></pre>
  
  <p>The issue is since there are <strong>two</strong> channels <code>database</code>/<code>mail</code> set in the Notification below, they <strong>both</strong> get added as queued jobs on the 'notifications' queue, set in the constructor. Instead, I want to add the mail channel below to an <code>emails</code> queue instead of the default one set in the constructor of 'notifications'.</p>
  
  <p>Any idea how to have the following notification only add the mail channel <code>MailMessage</code> to an <code>emails</code> queue <strong>without</strong> adding the <code>database</code> channel to a queue at all? (even if that means removing the constructor <code>onQueue</code>)</p>
  
  <pre><code>&lt;?php
  namespace App\Notifications;
  
  use Illuminate\Bus\Queueable;
  use Illuminate\Notifications\Notification;
  use Illuminate\Contracts\Queue\ShouldQueue;
  use Illuminate\Notifications\Messages\MailMessage;
  use App\Events\DogWasWalked;
  
  class DogWasWalkedNotification extends Notification implements ShouldQueue
  {
      use Queueable;
  
      protected $event;
  
      public function __construct(DogWasWalked $event) {
          $this-&gt;event = $event;
  
          // This is what creates 2 queued jobs (one per channel)
          $this-&gt;onQueue('notifications');
      }
  
      public function via($notifiable) {
          return ['database', 'mail'];
      }
  
      public function toArray($notifiable) {
          return [
              'activity' =&gt; 'Dog was walked!',
              'walkername' =&gt; $this-&gt;event-&gt;walkername
          ];
      }
  
      public function toMail($notifiable) {
        // How to set the queue name for
        // this channel to 'emails'
        return (new MailMessage)
               -&gt;line('Dog was walked!');
  
      }
  }
  </code></pre>