    it "should send an email with a return-path using exim" do
      Mail.defaults do
        delivery_method :exim
      end

      mail = Mail.new do
        to "to@test.lindsaar.net"
        from "from@test.lindsaar.net"
        sender "sender@test.lindsaar.net"
        subject "Can't set the return-path"
        return_path "return@test.lindsaar.net"
        message_id "<1234@test.lindsaar.net>"
        body "body"
      end
      
      Mail::Exim.should_receive(:call).with('/usr/sbin/exim',
                                                '-i -t -f "return@test.lindsaar.net"', 
                                                'to@test.lindsaar.net', 
                                                mail)
                                                
      mail.deliver

    end
The product receives input or data, but it does
        not validate or incorrectly validates that the input has the
        properties that are required to process the data safely and
        correctly.