mxext3.mailbox.org handles mail for 76 domain(s) we track — ordinary email domains.
This is one of several mail servers run by the same operator. mxext1.mailbox.org handles 79 domain(s) and has the fuller list.
See whether a specific domain is disposable, forwarding or safe — and which mail server it actually uses.
Enter a domain to look up its mail server and trust signals
Checking syntax, MX, SMTP, trust, gateway, and domain profile…
Enter a domain above and click Check to see results.
A mail server's reputation is one signal. The API scores every signup against the whole catalogue — disposable pools, low-trust domains, catch-alls and gateways — as it grows.
What you unlock