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MX Record Lookup – Check Any Domain's Mail Servers

Enter a domain to see which servers receive its email, in what order, and who runs them.

About MX Record Lookup

Run an MX record lookup when mail stops arriving after a move to Google Workspace or Microsoft 365, when a client says messages to you bounce, or when you want to know which provider a company uses before you contact their IT team. Type a domain, or paste an email address and the part after @ is used. Click Look up and the mail servers are listed by priority, lowest number first, with the IPv4 and IPv6 addresses each one resolves to. After switching mail providers, check that your SPF record includes the new one with the SPF Record Checker.

Each host is matched against 36 provider patterns, from Google Workspace and Microsoft 365 to Tencent Exmail, Alibaba Mail, Zoho, Proton Mail and Amazon SES. The checks flag a null MX (the domain refuses mail), no MX at all (senders fall back to the domain's own address), hosts without an address, and MX records that point to a CNAME alias or a bare IP, which the mail standards don't allow. Click a host name to open it in DNS Lookup. Lookups run when you click and aren't stored.

How to use MX Record Lookup

  1. 1
    Enter the domain

    Type a domain such as example.com, or paste an email address.

  2. 2
    Run the MX record lookup

    Click Look up to list the mail servers by priority, with their addresses and provider.

  3. 3
    Read the checks

    Each line says whether it passed or needs attention, with a fix for anything wrong.

  4. 4
    Copy or export

    Copy the Mail servers table, save it as CSV, or download the full result as JSON.

Why use Cubfile for this

  • Provider detection

    36 patterns recognize Google Workspace, Microsoft 365, Tencent Exmail, Alibaba Mail, Zoho, Amazon SES and more.

  • Addresses for every host

    Each mail server's IPv4 and IPv6 addresses, shown next to its priority.

  • Checks against the standards

    Null MX, missing MX, hosts that don't resolve, and MX pointing to a CNAME or an IP.

  • Linked results

    Click any mail server to see all of its DNS records.

FAQ

MX Record Lookup: questions and answers

What does the priority number in an MX record lookup mean?
Senders try the server with the lowest number first and move to higher numbers only if it doesn't answer. Servers with the same number share the load.
What happens if a domain has no MX record?
Senders fall back to the domain's own A or AAAA address, which is usually a web server, so mail tends to fail. With no address either, the domain can't receive email at all, while a null MX says on purpose that it accepts no mail.
Can an MX record point to a CNAME or an IP address?
It shouldn't. The standards require an MX target to be a host name with its own A or AAAA record, and senders handle anything else inconsistently, so point MX straight at the server's name.
I changed my MX records. Why does the lookup still show the old ones?
The lookup asks Cloudflare's public DNS, with Google and AliDNS as fallbacks, and resolvers keep records until their TTL runs out. Wait a while and look again, or compare 14 resolvers at once with the DNS Propagation Checker.
Is the MX record lookup free?
Yes, with no sign-up, and it doesn't use your daily tasks. An hourly allowance applies, higher for signed-in members, and results aren't stored.
Share MX Record Lookup with a friendIt runs in any browser, and they can try it without signing up.

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