instance method write_status

# File actionmailer/lib/action_mailer/vendor/tmail-1.2.3/tmail/port.rb, line 210
    def write_status( f, tag, flag )
      stat = ''
      File.open(@filename) {|r|
        while line = r.gets
          if line.strip.empty?
            break
          elsif m = /\AX-TMail-Status:/i.match(line)
            stat = m.post_match.strip
          else
            f.print line
          end
        end

        s = procinfostr(stat, tag, flag)
        f.puts 'X-TMail-Status: ' + s unless s.empty?
        f.puts

        while s = r.read(2048)
          f.write s
        end
      }
    end