Free MX lookup
MX Lookup
Free, no sign-up. We only fetch the public URL you enter.
Short answer
Enter a domain above and the MX lookup returns all of its MX (Mail Exchange) records, sorted by priority with the lowest number first, plus the IPv4 and IPv6 addresses each mail host resolves to. The lowest priority value is the server senders try first; higher values are fallbacks. No MX records, hosts that do not resolve or a host pointing to an IP address instead of a name are the classic causes of bounced or lost email. For your website itself, monitordefend watches uptime and response time every five minutes.
- Free, no sign-up: MX records sorted by priority.
- Resolves every mail host to its IPv4 and IPv6 addresses.
- Run it after switching email provider or moving DNS.
MX 1 aspmx.l.google.com → 142.250.153.27 MX 5 alt1.aspmx.l.google.com → 142.251.9.27 MX 5 alt2.aspmx.l.google.com → 64.233.184.27 MX 10 alt3.aspmx.l.google.com → 2a00:1450:400c:c0b::1b
This free MX lookup shows you in seconds which mail servers accept email for a domain. Enter a domain name and the tool queries its MX records, sorts them by priority and resolves every mail host to its IP addresses. That way you can validate your own mail setup after a change, verify server priorities, identify misconfigurations before messages bounce, or simply find out which email provider another domain uses.
What MX records are
MX stands for Mail Exchange. An MX record is a DNS entry that tells the rest of the internet which servers are responsible for receiving email for a domain. When someone writes to an address at your domain, their mail server does not guess where to deliver the message; it asks DNS for the MX records of the part after the @ and connects to the hosts listed there.
Each MX record has two parts: a priority value (also called preference) and the hostname of a mail server. A domain can publish one record or many. Correct MX records are critical for email delivery: if they are missing, point to the wrong place or name a host that no longer exists, incoming messages bounce, are delayed for days or vanish into an old mailbox nobody reads.
How the MX lookup works
Type a domain name such as example.com into the field above and start the check. The tool queries the public DNS for the MX records of that domain and lists them in a clear, easy-to-read table. The records are sorted by priority, so the server that senders try first is always at the top.
- Sender Wants to deliver to info@myshop.com
- DNS Asks for the MX records of myshop.com
- Priority Picks the lowest value first
- Mail server Accepts the message
For every mail host the lookup then resolves the name to its IPv4 (A) and IPv6 (AAAA) addresses. This second step matters: an MX record only contains a hostname, and a hostname that does not resolve is as good as no record at all. Seeing the addresses next to each host lets you confirm the whole chain from domain to reachable server in one view, with no sign-up and no personal data required.
- Priority value of each MX record, lowest first
- Hostname of every mail server
- IPv4 and IPv6 addresses each host resolves to
- A clear hint when a domain publishes no MX record
What the priority value means
The priority value decides the order in which sending servers try the mail hosts. Lower numbers win: a server with priority 10 is tried before one with 20, and a server with 1 before both. The absolute numbers carry no meaning beyond the order, so 10 and 20 behave exactly like 1 and 2.
If several records share the same priority, senders spread the load between them more or less at random. Providers use this for load balancing, which is why you often see two or three hosts with an identical value. Only when every server of the best priority fails does a sender move on to the next higher number.
How to interpret multiple MX records
Multiple MX records provide redundancy. If the highest-priority server is down for maintenance or overloaded, mail routes to the next server in line instead of being rejected. Most large email providers publish several hosts for exactly this reason, and you should keep all of them as your provider documents them.
- 10
mx1.myshop.com – not answering - 20
mx2.myshop.com – accepts the message
Redundancy only helps when every listed server is properly configured. A backup host that accepts mail for your domain but cannot forward it, or that has weaker spam filtering, becomes a weak spot. A frequent mistake is a leftover record from a previous provider: senders that pick it deliver into an account you closed months ago. When you read the lookup result, make sure every host in the list belongs to your current setup.
When you should run an MX lookup
An MX check is quick, so it is worth running whenever email routing could have changed or something feels off with incoming mail.
- After moving to Google Workspace, Microsoft 365 or another email provider
- After changing nameservers or moving your DNS to a new host
- When customers report bounced emails or messages that never arrive
- Before a domain migration, to note the current state
- To find out which provider handles mail for another domain
Common MX misconfigurations
The most serious problem is a missing MX record. Some senders then fall back to the A record of the domain and try to deliver to your web server, which usually rejects the message; others give up straight away. Either way, mail does not reach your inbox.
Next come records that point to a host without an address. The MX entry looks fine, but its target name has no A or AAAA record, perhaps because the server was renamed or deleted. The standard also requires the target to be a hostname, not an IP address, and not an alias defined by a CNAME; some senders tolerate these shortcuts, many do not. Finally, typos in hostnames and a forgotten trailing dot in zone files that silently appends your own domain create targets that do not exist. The resolved IP addresses in the result reveal all of these at a glance.
Setting up MX records correctly
Your email provider tells you exactly which MX records to publish, usually with hostnames and priority values ready to copy. Add them at the DNS provider that is actually responsible for your domain, that is the one your nameservers point to, and remove the records of any previous provider at the same time.
The MX record belongs on the domain your addresses use. For info@example.com that is example.com itself; a subdomain like mail.example.com only needs its own MX records if you send addresses to it. After saving, run the lookup again. Remember that DNS answers are cached for the duration of their TTL, so senders may use the old values for a while after the change. Lowering the TTL a day before a planned switch shortens that window.
MX records and email authentication
MX records only cover receiving mail. Whether your outgoing messages are trusted depends on three further DNS entries: SPF lists the servers allowed to send for your domain, DKIM publishes the public key used to verify signatures, and DMARC tells receivers what to do when those checks fail. A domain with perfect MX records can still land in spam if these are missing.
After switching email provider it is therefore worth checking all four. The SPF, DKIM and DMARC checkers on this site read those records and explain them in plain language, so you can confirm that receiving and sending are both in order.
Your website next to your mail
Mail and website often depend on the same DNS zone, and one careless change can break both. monitordefend does not monitor MX or other DNS records; use this lookup whenever you edit your zone. What monitordefend does watch is your website: the homepage is checked every five minutes, a second attempt confirms an outage, and you receive an email when it goes down or responds too slowly.
Frequently asked questions
What does the priority value mean for MX records?
It sets the order in which mail servers are tried. Lower numbers have higher priority and are tried first; if the server with 10 is unavailable, senders move on to the one with 20. Records with the same value share the load.
How can I find the MX records of any domain?
Enter the domain name in the MX lookup above. The tool retrieves all MX records from public DNS, sorts them by priority and resolves each mail host, without sign-up or personal information.
How do I interpret multiple MX records?
They provide redundancy and load balancing. Mail goes to the lowest priority first and falls back to the others when it is unavailable. Every listed server must belong to your current provider and be configured to accept your mail.
What happens if a domain has no MX record?
Some sending servers fall back to the A record and try to deliver to that address, which usually fails; others reject the message immediately. If you want to receive email, publish the MX records your provider gives you.
Can an MX record point to an IP address?
No. The standard requires a hostname that resolves through its own A or AAAA record. Pointing an MX record directly at an IP address or at a CNAME alias causes delivery failures with many senders.
How long do MX changes take to take effect?
That depends on the TTL of the old records. Resolvers keep cached answers until it expires, often between a few minutes and a day. Lower the TTL ahead of a planned switch for a faster changeover.
Why do my emails bounce although the MX records look right?
Check that each host resolves to an address, that no record of a former provider remains, and that the mailbox exists at your provider. Also verify SPF, DKIM and DMARC, because rejected outgoing mail often has nothing to do with MX records.