Free tool
Free MX record lookup
See which mail servers accept mail for a domain, and who actually runs them.
How this works
An MX record tells the world which servers accept mail for a domain. A domain with no MX records cannot receive mail at all — every address at it will bounce, no matter how well-formed it looks.
The priority number is a preference, not a rank of quality: lower is tried first, and the others are failover. Several records is normal and healthy.
The hostname usually gives away the provider, and that matters more than it looks. Google, Microsoft, Yahoo and Proton each behave differently when asked whether a mailbox exists — a verifier that treats them identically produces confidently wrong answers on at least two of them.
Questions, answered.
What is an MX record?
A DNS record naming the mail servers that accept mail for a domain, each with a priority. Lower priorities are tried first; the rest are failover.
What does it mean if a domain has no MX records?
It cannot receive mail. Any address at that domain will bounce regardless of how it is spelled — which is why a verifier should report "no MX" as undeliverable with certainty rather than as a guess.
Why do some domains have several MX records?
Redundancy. If the lowest-priority server is unreachable, senders fall back to the next. It is a sign of a well-run mail setup, not a problem.
Can I tell who hosts a company's email from its MX record?
Usually, yes — the hostname names the provider. This tool identifies the common ones for you, including Google Workspace, Microsoft 365, Zoho, Proton and the major mail gateways.