extract email addresses from inbox mails in gmail

get_mail.js

function sender_list() {
  var inbox_threads = GmailApp.getInboxThreads();

  var sender_array = new Array();

  for (var i = 0; i < inbox_threads.length; i++) {
    var message = inbox_threads[i].getMessages();
    for (var x = 0; x < message.length; x++) {            
      var email_address = retrieve_sender_from_message(message[x]);
      console.log(email_address);
      
      if (sender_array.indexOf(email_address) === -1)
        sender_array.push(email_address); 
    }
  }

  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = spreadsheet.getSheetByName('sheet1');
  sheet.clear();
  sheet.appendRow(['Email Addresses']);
  sender_array.sort();
  var row = sheet.getLastRow() + 1;
  for (var y = 0; y < sender_array.length; y++) {
    sheet.getRange(row, 1).setValue(sender_array[y]);
    row++;
  }
}

function retrieve_sender_from_message(message) {
  return message.getReplyTo() ? retrieve_email_from_sender(message.getReplyTo()) : retrieve_email_from_sender(message.getFrom());
}

// sender can be of the form `Name <name@provider.tld>` or `name@provider.tld`
function retrieve_email_from_sender(sender) {
  var opening_bracket = sender.indexOf('<');
  var closing_bracket = sender.indexOf('>');

  // this will likely fail if there are any users with a `<` or `>` in their name...
  if (closing_bracket !== 1 && opening_bracket !== 1) {
    return sender.substring(opening_bracket +1, closing_bracket);
  }
  
  return sender;
}