Script runs twice on google form submit trigger

Question

I'm create Google form and google app script with sendFormByEmail function, also I set on form submit trigger for this function, my issue is this script run two time on form submit and I'm getting two email, I want only single email on form submit. my script code is below.

var no_repeat=0;
function sendFormByEmail(e){

  var email = "[email protected]"; 

  var s = SpreadsheetApp.getActiveSheet();
  var headers = s.getRange(1,1,1,s.getLastColumn()).getValues()[0];    
  var message = "";
  var subject = "Success Assessment";
  var total=0;
  var roll_on=0;

  message+="test massage";
  message+="<table cellpadding='3' style='color: #0F1F4C;'>";
  for(var i in headers) { 
    if(headers[i]=='Please enter your email address to receive your results'){
      email=e.namedValues[headers[i]].toString();
    }
    if(headers[i]!='Please enter your email address to receive your results'){
      if(headers[i]!='Timestamp'){
        if(e.namedValues[headers[i]]!=''){      
          total = parseInt(e.namedValues[headers[i]])+parseInt(total);
        }

        message +="<tr >";
        message += '<td >'+headers[i]+'</td><td >'+e.namedValues[headers[i]].toString()+ "</td>";
        message +="</tr>";
        roll_on++;
      }
    }
  }  
  message +="<tr >";
  message += "<td ><b> YOUR SCORE </b></td><td ><b>"+total+"</b></td>";
  message+="</tr></table>";

  // Send the email

   if(email!='' && email!=null){
     if(no_repeat==0){ 
       MailApp.sendEmail(email, subject,"",{htmlBody: message});
     }
    no_repeat++; 
   }
}

Answer 1

This is a known issue at Google's end and they are working on a fix:

Our engineering team is working on the issue, but we don't have any estimates as to when it will be fixed. I advise applying the LockService logic as shown in update #22, which should work around the problem.