Enter an address above — MX is checked live, no server needed.
What runs here — and what needs the server
No server, all live in this page: syntax, disposable domains, role inboxes, typo detection, and a real-time MX record check via Google / Cloudflare DNS-over-HTTPS. Dead and non-existent domains are caught here — that's most hard bounces.
The one thing a browser can't do is the SMTP handshake (confirming the exact mailbox exists on a live domain). That's the Easy Serve API layer, on a port-25 server.
Host this file on easyserve.me or open it directly for live MX. If MX shows "couldn't reach resolver", the page is in a sandbox that blocks outside calls — hosting it fixes that.