title: Rails 3 - abandon sending mail within ActionMailer action
body: <p>I'm wondering how I could conditionally abandon sending mail within the action ActionMailer action itself.</p>
  
  <pre>
  <code>
  class SomeMailer &lt; ActionMailer::Base
    ...
  
    def some_emails
      some_models = Model.where(:a => 1)
      if !some_models.blank?
        mail(...)
      else
        # What to add here?
        # render :nothing => true doesn't work
      end
    end
  
  end
  </code>
  </pre>
  
  <p>Now invoking this through <code>SomeMailer.some_emails.deliver!</code> returns an 
  <code>ArgumentError: A sender (Return-Path, Sender or From) required to send a message</code></p>