Emails from the built-in Contact form have suddenly stopped reaching the site owner. Nothing has been updated or altered on this Drupal 8 installation since before the problem appeared, and we rely solely on the default Drupal mail system—no SMTP module or third-party service is currently configured. I need a thorough yet efficient investigation that pinpoints the root cause, restores reliable delivery, and explains what went wrong so it doesn’t happen again. Feel free to use any standard debugging tools you prefer—Drupal watchdog logs, Devel, SMTP or SendGrid test modules, even direct server log access if necessary—as long as the live site stays stable. Deliverables • Diagnose and fix whatever is blocking or dropping outgoing mail from the Contact form. • Confirm that test submissions arrive in the owner’s inbox. • Provide a short report outlining the issue, the fix you applied, and any preventive steps you recommend. Please work directly on the staging environment first (I’ll provide access) and migrate the solution to production once we verify everything works.