Inspect any domain's mail servers

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MX records lookup

See every MX record, IP, and email provider for any domain

Free MX records lookup for any domain. We query DNS, return every mail server in priority order, resolve IPv4 and IPv6 addresses, detect the email provider behind each MX, and flag null MX records.

Enter a domain. We query DNS in real time.

How to use this MX records lookup

Four steps from a domain name to a confident answer about its mail servers.

  1. 1

    Enter a domain

    Type any domain into the form above. Apex domains and subdomains both work.

  2. 2

    Submit

    We query authoritative DNS in real time. Results appear inline below the form.

  3. 3

    Read priorities, hosts, IPs, and providers

    Lower priority numbers are tried first. Each row shows the mail server, every resolved IPv4 and IPv6 address, and the detected email provider when we recognize one.

  4. 4

    Verify in your DNS provider

    If something is missing, open your DNS provider, find the MX records for the apex name, and confirm each entry matches what you expected to publish.

What you can learn from an MX records lookup

An MX records lookup is one of the fastest sanity checks for an email setup. Use it to:

  • Confirm Google Workspace or Microsoft 365 setup is complete after delegating mail to a new provider.
  • Spot a domain that explicitly accepts no email via a null MX record (RFC 7505).
  • Identify the email provider behind any sending domain by matching its MX hostnames to known providers.
  • Compare backup vs primary mail servers via priority numbers, and verify a failover path exists.
  • Cross-check MX hosts against MTA-STS and TLS-RPT policies on the same domain.
  • Audit a vendor or partner's email setup before sending high-volume mail to their addresses.

What is an MX record?

An MX record is the DNS entry that tells the internet which mail servers receive email for a domain. Each MX record points to a hostname and carries a numeric priority — lower priorities are tried first. To deliver email, sending servers query MX records, pick the lowest-priority host, resolve its IP, and connect to it on port 25. Without a published MX record, no one knows where to send your mail.

Beyond MX records

MX is one piece of email DNS. To stop spoofing and improve deliverability, also publish SPF, DKIM, and DMARC. Run a full check with our free domain checker or build your records with our SPF generator and DMARC generator.

Frequently asked questions

How do I look up MX records for a domain?
Enter the domain name into the form above and submit. Our MX lookup queries authoritative DNS, returns every MX record sorted by priority, resolves each mail server's IPv4 and IPv6 addresses, and identifies the email provider behind each MX host.
What is an MX record?
An MX (Mail Exchange) record is a DNS record that tells the rest of the internet which mail servers are responsible for receiving email for a domain. Without an MX record, mail sent to addresses on the domain has no defined destination and is typically rejected by sending servers.
What does MX record priority mean?
Each MX record has a numeric priority (also called preference). Lower numbers are tried first. If two MX records share the same priority, mail is load-balanced between them. Backup MX servers usually have higher priority numbers so they only receive mail when the primary servers are unreachable.
Can a domain have multiple MX records?
Yes. Most production domains publish two or more MX records to provide redundancy. Google Workspace, for example, typically lists five MX records at different priorities. Mail servers always try the lowest-priority record first and fall back to higher numbers when delivery fails.
Why does my domain have no MX records?
Three common reasons: the domain is configured for outbound email only and never receives mail, the MX record was never published in DNS (a misconfiguration), or the domain has a null MX record (a single MX with priority 0 and host '.') signalling that it explicitly does not accept email per RFC 7505.
What is a null MX record?
A null MX record (RFC 7505) is a single MX record of the form '0 .' that explicitly tells the internet a domain does not accept email. Sending mail servers see the null MX and immediately reject delivery rather than retrying for days. Use it on parked domains, brand-protection domains, and any domain that should never receive mail.
Is this MX records lookup tool free?
Yes. The MX lookup tool is completely free with no signup required. We rate-limit per IP to prevent abuse, but normal use is unrestricted.