/// <summary>
 /// 夾帶檔案
 /// </summary>
 public void AttachmentFile(byte[] bytes, string filename)
 {
     EmailFiles.Add(new EmailFileDTO()
     {
         FileName = filename, MemoryStream = new MemoryStream(bytes)
     });
 }
 /// <summary>
 /// 夾帶檔案
 /// </summary>
 public void AttachmentFile(MemoryStream memoryStream, string filename)
 {
     EmailFiles.Add(new EmailFileDTO()
     {
         FileName = filename, MemoryStream = memoryStream
     });
 }