### rake routes [plain_text]
   domain_mailboxes GET    /domains/:domain_id/mailboxes(.:format)          {:controller=>"mailboxes", :action=>"index"}
                    POST   /domains/:domain_id/mailboxes(.:format)          {:controller=>"mailboxes", :action=>"create"}
 new_domain_mailbox GET    /domains/:domain_id/mailboxes/new(.:format)      {:controller=>"mailboxes", :action=>"new"}
edit_domain_mailbox GET    /domains/:domain_id/mailboxes/:id/edit(.:format) {:controller=>"mailboxes", :action=>"edit"}
     domain_mailbox GET    /domains/:domain_id/mailboxes/:id(.:format)      {:controller=>"mailboxes", :action=>"show"}
                    PUT    /domains/:domain_id/mailboxes/:id(.:format)      {:controller=>"mailboxes", :action=>"update"}
                    DELETE /domains/:domain_id/mailboxes/:id(.:format)      {:controller=>"mailboxes", :action=>"destroy"}

### routes.rb [ruby_on_rails]

  map.resources :domains, :has_many => [:mailboxes, :aliases]