gistfile1.rb

# mailer_twitterable/lib/supercoco9/mailer_twitterable.rb 
module Supercoco9
  module MailerTwitterable 
    def self.included(base) 
      base.extend ClassMethods 
      base.include InstanceMethods 
    end 
    module ClassMethods
      def deliver_with_twitterable!(mail=@mail)
        # ... your code here
        deliver_without_twitterable!   
      end
      alias_method_chain :deliver!, :twitterable

    end
 
    module InstanceMethods 
    end 
  end 
end