MX record lookup
See a domain's mail servers in priority order, the provider running them, and whether the domain accepts mail at all — from a live DNS query, free.
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What MX records are
MX (mail exchanger) records are the DNS entries that tell the world where a domain's email should be delivered. Each record names a host and a priority; senders try the lowest priority first and fall back down the list. A domain without working mail hosts cannot receive email — which is why an MX check is the first meaningful step of verifying any address at that domain.
How to read the result
"Accepts mail" means the domain publishes MX hosts — or, per RFC 5321, has an A/AAAA record acting as the implicit fallback. "No mail server found" means neither exists, so every address at the domain is undeliverable. "Declines all mail" is the special null MX case: the domain has actively declared it receives nothing. The provider line classifies the hosts against known infrastructure patterns — google, microsoft, proofpoint, zoho, and about twenty others.
Frequently asked questions
What if a domain has no MX records?
It can still receive mail. RFC 5321 defines an implicit fallback: when no MX records exist, senders deliver to the domain's A or AAAA record directly. This tool follows the same rule, so a domain with only an A record still reports "accepts mail" with itself as the host.
What is a null MX record?
A single MX record with priority 0 and an empty target ("0 .") is a null MX (RFC 7505). It is the domain explicitly declaring that it never accepts mail — any address at such a domain is undeliverable, and senders should not retry.
Why do the mail hosts matter for email verification?
The MX hostnames reveal which infrastructure runs the domain's mail — Google Workspace, Microsoft 365, Proofpoint, and so on. That tells you whether a mailbox-level check is possible and how the server tends to behave, such as catch-all acceptance.
Data synced on 2026-10-12: the newest sync of the open lists and curated maps behind every answer on this page. The domain's own records are read live at each check.
More free tools
All free toolsNeed this at scale?
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