Is it possible to send a string in mail.Body?

I want to send the string survey in mail.body. Everytime I "Send Email" mail.Body as empty. When I use Debug.Log(survey); i get all the correct data in the console but nothing shows up in the email.

using System.IO; using System.Text; using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.UI; using UnityEngine.Networking; using System.Net; using System.Net.Mail; using System.Net.Security; using System.Security.Cryptography.X509Certificates;

public class SubmittingBehaviour : UI_AbstractMenuBehaviour {

 [SerializeField] Text InfoText;
 [SerializeField] Text CloseButtonText;
 public int savedCount = 0;
  

 public MainMenuBehaviour MainBehaviour;
 public string survey;

 // Use this for initialization
 void Start () {
     CloseButtonText.text = MainMenuBehaviour.CurrentDictionary.GetKeyValue("cancel");
     //activate ths, if you want to send  data
     InfoText.text = MainMenuBehaviour.CurrentDictionary.GetKeyValue("sending_data",false);
     Questionaire questionaire = MainBehaviour.GetCurrentQuestionaire();
     SaveSurveyToJson saveSurvey = new SaveSurveyToJson(questionaire);
     survey = JsonUtility.ToJson(saveSurvey);
     **Debug.Log(survey);**
     
     //how many saves so far?
     int savedCount = 0;
     if (PlayerPrefs.HasKey("SavedCount"))
     {
         savedCount = PlayerPrefs.GetInt("SavedCount");
     }
     SaveLocal(survey, savedCount);
     //TODO
     //Activate this, if you want to send the data to a server
   /*  StartCoroutine( PushToServer(survey,savedCount));*/
     savedCount++;
     PlayerPrefs.SetInt("SavedCount", savedCount);
 }

  
 /// <summary>
 /// Save results as a json file  in persistant data path
 /// </summary>
 /// <param name="survey">Survey.</param>
 /// <param name="id">Identifier.</param>
  

void SaveLocal(string survey, int id) { //save to disk string fileName = "results" + id.ToString("D4"); print("Filename: " + fileName); Debug.Log(Application.persistentDataPath);

     string filePath = Application.persistentDataPath + "/"+fileName + ".json";
     //string path = Application.persistentDataPath;

     //SendEmail.(MailMessage);
     byte[] JsonStringBytes = Encoding.UTF8.GetBytes(survey);
     File.WriteAllBytes(filePath, JsonStringBytes);

InfoText.text += "\n\n" + MainMenuBehaviour.CurrentDictionary.GetKeyValue("saved_locally", false);

 }
 

  
 public void SendEmail()
 {
     MailMessage mail = new MailMessage();

     mail.From = new MailAddress("sender@gmail.com");
     mail.To.Add("reciever1@gmail.com");
     mail.To.Add("reciever2@gmail.com");
     mail.To.Add("reciever3@gmail.com@gmail.com");

     mail.Subject = "Test Mail";
   //  mail.Body = "This is for testing SMTP mail from GMAIL";
  mail.Body = survey;
     Debug.Log(mail.Body); 

     SmtpClient smtpServer = new SmtpClient("smtp.gmail.com");
     smtpServer.Port = 587;
     smtpServer.Credentials = new System.Net.NetworkCredential("sender@gmail.com", "senderpassword") as ICredentialsByHost; 
     smtpServer.EnableSsl = true;
     ServicePointManager.ServerCertificateValidationCallback =
         delegate (object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
         { return true; };
     smtpServer.Send(mail);
     Debug.Log("success");

 }

   

}