MX Lookup - Check MX Records for Any Domain
Email that silently bounces usually traces back to one thing: broken or missing MX records. Check any domain free, no signup.
A lookup shows every mail exchange server with its priority value, resolved IP address, TTL, and the network behind it, including ASN, operating organization, server location, and abuse contacts. You also get the domain's A, AAAA, and CNAME records in a raw DNS tab, plus a status that says at a glance whether the domain can receive email. Paste a bare domain, a full URL, or an email address; an email MX lookup checks the domain after the @ sign.
Copy any hostname, IP, or the raw DNS records straight from the results. Nothing to install.
How to Check MX Records with This Tool
To check MX records for a domain with this MX lookup tool:
- Enter a domain name: such as amazon.com. A full URL or an email address works too — the lookup runs against the bare domain either way.
- Run the MX lookup: the tool queries live DNS to find MX records for the domain, then resolves each mail server hostname to its IP address and network details.
- Read the record status first: Valid, No Mail, Partial, No Record, or Invalid tells you immediately whether the domain can receive email. Mail servers are listed in priority order; the first one opens with its network details, and you can open any other to load its IP, ASN, and abuse contact. Switch to the Raw DNS Records tab to copy the records as your resolver returned them.
Understanding Your MX Lookup Results
Every MX record lookup returns a status plus a detailed entry per mail server. Here's how to read each field this MX checker reports:
Record Status
The first thing to check.
- Valid: all MX records are present and properly formatted; the domain is configured to receive email.
- No Mail: the domain publishes a null MX record (priority 0, target
.), which tells every sender it accepts no email. That is a deliberate setting, not a fault. - Partial: no MX records found, but other DNS records (A, AAAA, or CNAME) exist. The domain is registered and resolves, but it is not set up to receive email.
- No Record: no MX, A, AAAA, or CNAME records at all; the domain may be unregistered or has no DNS configuration.
- Invalid: an MX record is malformed, points at an IP address instead of a hostname, or the domain mixes a null MX with real mail servers.
Mail Servers
How many MX records the domain publishes. A null MX counts as zero, because it names no server. A single record is normal for Google Workspace's current setup; self-hosted mail usually runs two or more so a backup can take over.
Priority
Lower numbers are tried first. A domain with records at priority 10 and 20 delivers to the priority-10 server and falls back to 20 if it's unreachable. Servers that share a number split incoming mail between them. The tool sorts every result by priority, so the server listed first is the one senders try first.
IP Address
ASN, Organization, and Server Location
Abuse Contacts and Network Range
TTL
How long resolvers cache each record. High TTLs mean MX changes propagate slowly; check TTLs before scheduling a mail migration.
Raw DNS Records
The domain's A, AAAA, and CNAME records in a separate tab, so you can see how the domain itself resolves alongside its mail configuration.
Expected MX Records for Common Email Providers
Find MX records for your domain with the lookup above, then compare the servers against the values your provider publishes. If the hostnames match but mail still doesn't arrive, the problem is usually on the provider's side of setup, such as a mailbox or domain that hasn't been activated yet.
| Provider | Mail server (MX target) | Priority |
|---|---|---|
| Google Workspace (current setup, 2023 onward) | smtp.google.com | 1 |
| Google Workspace (legacy five-record setup) | aspmx.l.google.com · alt1.aspmx.l.google.com · alt2.aspmx.l.google.com · alt3.aspmx.l.google.com · alt4.aspmx.l.google.com | 1 · 5 · 5 · 10 · 10 |
| Microsoft 365 / Exchange Online | <MX token>.mail.protection.outlook.com | 0, and the lowest on the domain |
| Microsoft 365 with DNSSEC enabled | <domain>.<suffix>.mx.microsoft | 0, and the lowest on the domain |
| Zoho Mail | mx.zoho.com · mx2.zoho.com · mx3.zoho.com | 10 · 20 · 50 |
Google still supports the legacy set, and a working legacy domain doesn't need to switch. Microsoft's MX token is unique to each domain and shown in the Microsoft 365 admin center. Zoho's domain ending changes with the data center that hosts your account, so copy the exact values from the Zoho admin console.
aspmx.l.google.com at 10, two ALT servers at 20, and two googlemail.com servers at 30. Senders only compare the numbers against each other, so that order routes mail the same way as 1, 5, 10. For Google-hosted mail, the Organization field in the results reads Google LLC under AS15169.How MX Records Route Email
An MX (Mail Exchange) record is a DNS entry that names a server accepting email for a domain, together with a priority number. Every sending server runs an MX lookup before it delivers, so these records decide where a domain's mail goes, or whether it goes anywhere.
Priority and Fallback
Senders try the lowest number first and move to the next only when a server doesn't answer. Records at the same number share the load in random order, which is why Google's legacy setup pairs its ALT servers. The numbers carry no meaning beyond the order they create.
What an MX Record Can Point To
A hostname that resolves to an A or AAAA record, and nothing else. An IP address in the MX field breaks the DNS standard and many senders refuse to deliver to it; this tool marks that as Invalid. RFC 2181 also rules out pointing an MX record at a CNAME alias.
Null MX: A Domain That Takes No Email
. to announce that a domain accepts no email. Senders reject messages at once instead of retrying for days. Parked domains and send-only domains should publish one; this tool reports it as No Mail. A null MX must stand alone: mixed with real mail servers, it shows as Invalid.When There Is No MX Record
Senders fall back to the domain's own A or AAAA record and try to deliver there. If nothing at that address accepts mail, messages wait in retry queues for days before bouncing. The tool reports this as Partial: the domain resolves, but nothing says where its mail should go.
Check MX Records from the Command Line
You can run a DNS MX lookup without a browser using tools built into your OS. On Windows, open Command Prompt and run:
nslookup -type=mx amazon.comOn macOS or Linux, use dig:
dig amazon.com mx +shortdig output through three more lookups.