    def encoded_with_jpmobile(transfer_encoding = '8bit')
      if @mobile && !multipart?
        case transfer_encoding
        when /base64/
          _raw_source = if transfer_encoding == encoding
                          @raw_source.dup
                        else
                          negotiate_best_encoding(transfer_encoding).encode(@raw_source)
                        end
          Jpmobile::Util.set_encoding(_raw_source, @mobile.mail_charset(@charset))
        when /quoted-printable/
          Jpmobile::Util.set_encoding([@mobile.to_mail_body(@raw_source)].pack('M').gsub(/\n/, "\r\n"), @mobile.mail_charset(@charset))
        else
          @mobile.to_mail_body(Jpmobile::Util.force_encode(@raw_source, nil, Jpmobile::Util::UTF8))
        end
      else
        encoded_without_jpmobile(transfer_encoding)
      end
    end