Mailgun Interceptor?

# This interceptor just makes sure that local mail 
# only emails you.
# http://edgeguides.rubyonrails.org/action_mailer_basics.html#intercepting-emails
class DevelopmentMailInterceptor
  def self.delivering_email(message)
    message.to =  '[email protected]'
    message.cc = nil
    message.bcc = nil
  end
end

# Locally, outgoing mail will be 'intercepted' by the
# above DevelopmentMailInterceptor before going out
if Rails.env.development?
  ActionMailer::Base.register_interceptor(DevelopmentMailInterceptor)

Chris - what is the purpose of the interceptor code above? Is it mainly to test the email canbe sent out? I'm guessing the flow is:

• I send an email locally from my Rails app (not from my email client like gmail or Mail.app)
• The interceptor gets triggered and doesn't actually send the email, but stops it from being sent