how does this look

mailer_observer.rb

class MailerObserver < ActiveRecord::Observer
  observer :device, :device_problem, :device_location

  def after_create(device_problem)
    DeviceMailer.problem_device(device_problem.device).deliver
  end

  def after_save(device_location)
    # count active device_locations for location and check against par_levels
    # send alert email if necessary
  end

end