Enter any domain, pick a record type, and see the live records with their TTLs, read straight from public DNS.
Loading tool…
Lower stack cost. Back in the inbox. Built to send at any scale.
We rebuild it properly: secondary domains, inboxes, SPF, DKIM and DMARC set to enforcement, warmup and safe sending limits, blacklist monitoring on top. Send-ready in about 17 days. No campaigns, no copy, no lead lists. Infrastructure only.
Almost a decade building cold outreach infrastructure, including his own sending and verification stack built from scratch. 20+ B2B clients at companies worth $10M and above, all in tier one countries.
Free · Written plan + fixed price · No sales call required
DNS is the phone book behind a domain. When you type a name, DNS turns that name into the addresses and settings a computer needs: where the website lives, where email is delivered, which nameservers hold the zone, and what text records say about the domain. A DNS lookup asks public DNS for one kind of record at a time and shows you the live answer, exactly as it is published.
That makes a lookup the fastest first check when something looks wrong. If a site will not load, if mail is not arriving, or if a change you made does not seem to have taken, the records here show what the rest of the internet is being told about your domain right now.
Every record comes with a TTL, its time to live, written in seconds. The TTL tells resolvers how long they may cache that answer before they must ask again. A TTL of 3600 means an answer may be kept for one hour. A TTL of 14400 means four hours. A long TTL makes lookups a little lighter, but a change takes longer to be seen everywhere. A short TTL updates faster, at the cost of more lookups.
If you have just changed a record and still see the old value, the TTL on the old answer is usually the reason.
Look up coldmailkit.com with the record type set to MX. The answer returns two records: 5 mx1.hostinger.com and 10 mx2.hostinger.com, each with a TTL of 14400. The numbers 5 and 10 are the priorities: mail is delivered to the lowest number first, so mx1 is tried before mx2, and mx2 is the backup if mx1 does not answer. The TTL of 14400 means resolvers may cache the answer for 4 hours.
A blank result usually has one of three plain causes. First, you may be asking for the wrong record type: a domain can have A and MX records and still have no SRV record at all. Second, the record may still be propagating: you added it, but resolvers are still serving a cached older answer until its TTL runs out. Third, the record truly does not exist: it was never added, it was added at the wrong host, or it was removed. Check the type, check the spelling, and give a new record time before you conclude it is missing.
If a change is still spreading, watch it with the DNS Propagation Checker. For a full picture of one domain, run the Domain Health Checker. To read mail records on their own, use the MX Record Checker, and to see how old a domain is, use the Domain Age Checker.
A DNS lookup is a question sent to the Domain Name System for one kind of record about a domain, such as its address or its mail servers. The answer is the record as it is published in DNS right now, together with its TTL.
Each type carries a different kind of fact. A and AAAA carry addresses, CNAME carries an alias, MX names the mail servers, TXT holds text such as SPF, NS names the nameservers, SOA holds zone timing, CAA names who may issue certificates, and SRV names the host and port for a service.
TTL is time to live, in seconds. It tells resolvers how long they may cache the answer before asking again. A TTL of 14400 is four hours, so a change to that record can take up to four hours to be seen by everyone.
The most common reason is caching. Resolvers that asked before your change keep serving the old answer, or an empty one, until the old TTL expires. A wrong record type or a record added at the wrong host can also cause it. Wait for the TTL, then check again.
NXDOMAIN is the DNS answer for a name that does not exist. It is stronger than an empty result: DNS is saying there is no such name at all, which is often a spelling mistake, a subdomain that was never created, or a domain that is not registered.
Enter the domain above, set the record type to MX, and run the check. The answer lists each mail server with its priority. The lowest priority number is the server mail is delivered to first.
Yes. Enter the full subdomain, such as mail.example.com, instead of the main domain. DNS records are published per name, so a subdomain can have its own A, TXT and other records, separate from the records at the root.
The question is sent from your browser to public DNS each time you run it, so it is as live as that resolver can give. The resolver itself may answer from its cache until the TTL of the record runs out, which is why a brand new change is not always visible at once. This tool shows the TTL with each record so you can see how long a cached answer may last.
It covers what is broken, what we would build, the timeline, and one fixed price. Want it walked through instead? Book a 15 minute plan walkthrough.
Or just reply to the plan email. Either works.
