MX lookup
Find any domain's mail servers in the order they are tried, and the email provider behind them. Paste a domain or a full email address. No signup.
Same check from your code
The API returns mx_found and mx_provider on every email score, treats a domain with no MX as one that cannot receive mail, and combines that with SPF, DMARC, domain age and disposable detection into one risk score per address.
curl "https://www.layercall.com/v1/verify/email?email=anyone@example.com" \ -H "x-api-key: YOUR_KEY"
1,000 lookups a month free, no card. Get a key or read the docs.
What each signal means
Priority
Each MX record carries a number. Sending servers try the lowest first and fall back to higher ones if it does not answer.
The order is the configuration. A domain with one record has no fallback; a domain with several at equal priority is load-balancing across them, which is what every large provider does.
Mail server host
The hostname that accepts mail for the domain — usually not the domain itself.
It is how the provider is identified. aspmx.l.google.com is Google Workspace, *.mail.protection.outlook.com is Microsoft 365, and a hostname on the domain's own name usually means self-hosted.
Provider
The service behind the MX hosts, matched from the same list our email scoring uses.
It tells you two things at once: the domain is genuinely set up to receive mail, and roughly how seriously — a business on Google Workspace or Microsoft 365 is a different kind of domain from one pointing at a free forwarder.
No MX at all
The domain publishes no mail exchanger.
Then it cannot receive email, and any address on it is not a working address. Our email scoring treats this as a hard fact: status invalid, and the risk score goes up, because an address that provably cannot receive mail is either a typo or a fabrication.
Questions
What is an MX record?
A DNS record that says which server receives email for a domain. When someone sends to anyone@example.com, their mail server looks up the MX records for example.com and delivers to the host with the lowest priority number that answers. Without MX records there is nowhere to deliver to.
Why does a domain have several MX records?
Redundancy and load. Records at different priorities are a fallback chain — if the first is down, try the next. Records at the same priority are tried in random order, spreading the load across them. Google publishes five; Microsoft typically one, with the redundancy handled behind it.
Can I look up an email address instead of a domain?
Yes. Paste the whole address and the tool uses the part after the @. MX records belong to the domain, not to individual addresses, so this tells you whether the domain can receive mail — not whether that particular mailbox exists.
The domain has no MX records. Can it still receive email?
Technically, some senders fall back to the domain's A record and try port 25 there, as the RFC once required. In practice most modern mail servers do not, and a domain relying on that fallback is either misconfigured or was never meant to receive mail. Treat no MX as no mail.
How is the provider identified?
By matching the MX hostnames against a list of known providers — the same list our email scoring uses, so the tool and the API never call the same host two different things. A hostname on the domain itself, or one not on the list, shows no provider; that usually means self-hosted or a smaller service.
Does the MX record affect fraud scoring?
Directly. An email address on a domain with no MX cannot receive mail, so the address is invalid whatever else is true about it — a typo, or a company domain that was invented to look plausible. Beyond that, the provider is a weak but real signal: a paid business mail platform and a free forwarding service describe different kinds of domain.