public string SendMessage(Message message, Recipient recipient, string smsUrl)
 {
     try
     {
         SendMessage(message.MessageText, recipient.MobileNo.ToString(), smsUrl);
     }
     catch (Exception ex)
     {
         return "FAIL send message: " + ex.Message;
     }
     return "Message sent successfully.";
 }
 public string SendMessage(Message message, RecipientGroup recipientGroup, string smsUrl)
 {
     IList<string> recipientMobileNos = GetRecipients(recipientGroup.Id.Value).Select(r => r.MobileNo.ToString()).ToList();
     try
     {
         SendMessage(message.MessageText, string.Join(",", recipientMobileNos), smsUrl);
     }
     catch (Exception ex)
     {
         return "FAIL send messages: " + ex.Message;
     }
     return "Messages sent successfully.";
 }