Auto delete old IESL emails from gmail

Code.gs

function auto_trash_old_iesl_emails() {
  const emails = GmailApp.search('from:ieslweb@iesl.lk')
  if (emails.length === 0) {
    // return if no email found
    console.log("No emails found!")
    return
  }
  
  for (const email of emails) {
    const lastUpdateOn = email.getLastMessageDate()

    const age = ((new Date()) - lastUpdateOn) / (1000 * 60 * 60 * 24) // in days
    if (age > 7) {
      console.log('Moving ', email.getFirstMessageSubject(), ' to trash, ', age, ' days old')
      email.moveToTrash()
    }
  }
}