instance method accept

# File actionmailer/lib/action_mailer/vendor/tmail-1.2.3/tmail/mail.rb, line 169
    def accept( strategy )
      with_multipart_encoding(strategy) {
          ordered_each do |name, field|
            next if field.empty?
            strategy.header_name canonical(name)
            field.accept strategy
            strategy.puts
          end
          strategy.puts
          body_port().ropen {|r|
              strategy.write r.read
          }
      }
    end