Free developer tools
Email DNS Check (SPF, DMARC, MX)
See if a domain has MX, SPF and DMARC records set, and what is missing for good email delivery.
Uses public DNS. Nothing you type is stored.
Uses public DNS (Cloudflare) from your browser.
Need more? Try Website Monitor
Check that your site is up, fast, on HTTPS and unchanged — once now or on a schedule.