code: @Override
      public String sendMMS(String CorpNum, String sender, String senderName,
                            String subject, String content, Message[] Messages, File file,
                            Date reserveDT, Boolean adsYN, String UserID, String requestNum)
              throws PopbillException {
          if (Messages == null || Messages.length == 0)
              throw new PopbillException(-99999999, "전송할 메시지가 입력되지 않았습니다.");
  
          SendRequest request = new SendRequest();
          request.snd = sender;
  
          request.content = content;
          request.subject = subject;
  
          if (senderName != null)
              request.sndnm = senderName;
  
          if (adsYN) {
              request.adsYN = true;
          } else {
              request.adsYN = false;
          }
  
          if (reserveDT != null)
              request.sndDT = new SimpleDateFormat("yyyyMMddHHmmss", Locale.KOREA)
                      .format(reserveDT);
  
          request.msgs = Messages;
  
          if (requestNum != null)
              request.requestNum = requestNum;
  
          String PostData = toJsonString(request);
  
          List<UploadFile> uploadFiles = new ArrayList<UploadFile>();
  
          UploadFile uf = new UploadFile();
          uf.fieldName = "file";
          uf.fileName = file.getName();
          try {
              uf.fileData = new FileInputStream(file);
          } catch (FileNotFoundException e) {
              throw new PopbillException(-99999999, "전송할 파일을 찾을 수 없습니다.", e);
          }
          uploadFiles.add(uf);
  
          ReceiptResponse response = httppostFiles("/MMS", CorpNum,
                  PostData, uploadFiles, UserID, ReceiptResponse.class);
  
          return response.receiptNum;
      }
docs: /*
  (non-Javadoc)
  @see com.popbill.api.MessageService#sendMMS(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, com.popbill.api.message.Message[], java.io.File, java.util.Date, java.lang.Boolean, java.lang.String)