I'm sending emails using google appscript I had 1500 DailyQuata before I executed my code once which send 3 emails, but my Daily quota becomes 1485 afterward. as I sent 3 emails it should have only gone down by 3

Daily Quota limit showing 1485

My spreadsheet is as follows google Spreedsheet

entire code

function onOpen() {
  var ui = SpreadsheetApp.getUi();
  ui.createMenu('Automation')
    .addItem('send PDF Form', 'sendPDFForm')
    .addItem('send to all', 'sendFormToAll')
    .addToUi();
  console.log(MailApp.getRemainingDailyQuota())
}

function sendPDFForm() {
  var row = SpreadsheetApp.getActiveSheet().getActiveCell().getRow();
  sendEmailWithAttachment(row);
}

function sendEmailWithAttachment(row) {
  var client = getClientInfo(row);
  var file = DriveApp.getFilesByName(client.filename);
  if (!file.hasNext()) {
    console.error("Could not open file " + client.filename);
    return;
  }
  var template = HtmlService.createTemplateFromFile('email-template');
  template.client = client;
  var message = template.evaluate().getContent();
  MailApp.sendEmail({
    to: client.email,
    subject: "Engineer's Day participation Certificate",
    htmlBody: message,
    attachments: [file.next().getAs(MimeType.JPEG)]
  });

}

function getClientInfo(row) {
  var sheet = SpreadsheetApp.getActive().getSheetByName('Sheet1');
  var values = sheet.getRange(row, 1, 1, 5).getValues();
  var rec = values[0];
  console.log(rec)
  var client ={filename: rec[4],name: rec[1],first_name: rec[2],email: rec[3]};
  return client;
}

function sendFormToAll() {
  var sheet = SpreadsheetApp.getActive().getSheetByName('Sheet1');
  var last_row = sheet.getDataRange().getLastRow();
  console.log(last_row)
  for (var row = 2; row <= last_row; row++) {
    sendEmailWithAttachment(row);  //sending email
    Utilities.sleep(300);
    sheet.getRange(row, 7).setValue("email sent");
  }
}

I have checked the value of last_row it 4 so the loop runs only 3 times.

edit: I used sendFormToAll() function to send emails