    # File lib/rfilter/deliver.rb, line 115
        def write_to_mbox(output_io, message)
          first = true
          message.each { |line|
            if first
              first = false
              if line !~ /^From .*\d$/
                from = "From foo@bar  " + Time.now.asctime + "\n"
                output_io << from
              end
            elsif line =~ /^From /
              output_io << '>'
            end
            output_io << line
            output_io << "\n" unless line[-1] == ?\n
          }
          output_io << "\n"
        end