Gmail filtering into google Spread Sheet

Code.gs

function createHeaders(sheet) {
  
  // The SpreadSheet headers
  var headers = ["Subject", "First Message From", "First Message Date", 
                 "Message Count", "Last Message Date", "Have we replied?"];
  
  // Let's give the columns some info
  sheet.appendRow(headers);
  
  // Bold the first row for the headers
  sheet.getRange(1, 1, 1, headers.length).setFontWeight("bold")
}

function mainFunction() {
  
  var myEmail = "<[email protected]>";
  
  // URL to SpreadSheet located in Google docs
  var spreadSheet = SpreadsheetApp.openByUrl(
    'https://docs.google.com/spreadsheets/d/<WORK-SHEET-ID>/edit');
  
  // The first Sheet of the SpreadSheet
  var sheet = spreadSheet.getSheets()[0];
  
  createHeaders(sheet);
  
  // Get all Inbox Message Threads (A Thread has multiple messages... email chain)
  var threads = GmailApp.getInboxThreads();
  
  // Loop through first 5 Threads as an example
  for (var i = 0; i < 5; i++)
  {
    // Get the thread Subject Line
    var threadSubject = threads[i].getFirstMessageSubject();
    
    // Get the last message timestamp
    var latestTimestamp = threads[i].getLastMessageDate();
    
    // All Messages within email chain
    var messages = threads[i].getMessages();
    
    // When was the first message sent
    var firstMessageDate = messages[0].getDate();
    
    // Who sent the first message
    var firstMessageFrom = messages[0].getFrom();
    
    // How many messages in the email chain
    var messageCount = messages.length;
    
    // The last message in the email chain...
    var lastMessageInThread = messages[messageCount - 1];
    
    // We look to see if the last message in the chain 
    // was sent from your email address
    var didNativeReply;
    
    if(lastMessageInThread.getFrom().indexOf(myEmail) > -1)
    {
      didNativeReply = "Replied To Last Message";
    }
    else
    {
      didNativeReply = "Haven't Replied To Last Message";
    }
    
    sheet.appendRow([threadSubject, firstMessageFrom, firstMessageDate, 
                     messageCount, latestTimestamp, didNativeReply]);
  }
}