title: ActionMailer, Sneakers, deliver_later function
body: <p>I have next code:</p>
  
  <pre><code># Gemfile
  gem 'sneakers'
  
  # application.rb
  config.active_job.queue_adapter = :sneakers
  
  # application_mailer.rb
  class ApplicationMailer &lt; ActionMailer::Base
  ...
    def send_letter(params={})
      mail(params)
    ...
    end
  end
  
  # my_mailer_controller.rb
  def send_my_mail
    ApplicationMailer.send_letter(params).deliver_later
  end
  </code></pre>
  
  <p>rabbitmq-server is installed and started.
  When I run 'send_my_mail' function I receive in Rails console message:</p>
  
  <pre><code>[ActiveJob] Enqueued ActionMailer::DeliveryJob (Job ID: b2c66a30-70d1-4bba-a88e-d6260443347d) to Sneakers(mailers) with arguments: "ApplicationMailer", "send_letter", "deliver_now", ...
  </code></pre>
  
  <p>But when I run ActiveJob worker using terminal command:</p>
  
  <pre><code>WORKERS=ActiveJob::QueueAdapters::SneakersAdapter::JobWrapper rake sneakers:run
  </code></pre>
  
  <p>nothing happens. Looks like the mailer listener with correct class name does not start so the letters are not sent. In Rabbitmq UI tracer I see record for message event:</p>
  
  <pre><code>Node:         rabbit@ubuntu-trusty-64
  Connection:   127.0.0.1:35834 -&gt; 127.0.0.1:5672
  Virtual host: /
  User:         guest
  Channel:      1
  Exchange:     sneakers
  Routing keys: [&lt;&lt;"mailers"&gt;&gt;]
  Routed queues: []
  Properties:   [{&lt;&lt;"priority"&gt;&gt;,signedint,0},
                 {&lt;&lt;"delivery_mode"&gt;&gt;,signedint,2},
                 {&lt;&lt;"content_type"&gt;&gt;,longstr,&lt;&lt;"application/octet-stream"&gt;&gt;}]
  Payload: 
  {"job_class":"ActionMailer::DeliveryJob","job_id":"7a58ab27-d110-4e8b-911b-fe821735e1b7","queue_name":"mailers","arguments":["ApplicationMailer","send_newsletter","deliver_now",...
  </code></pre>
  
  <p>What is the correct WORKER name for 'deliver_later' Active Job and Sneakers?
  Thank you.</p>