DNS translates human-readable domain names into the information computers require to route traffic — IP addresses, mail server destinations, ownership verification tokens, and more. A domain does not have a single DNS record; it has several distinct types, each answering a different question. Understanding what each type does is the key to reading a DNS Lookup result correctly.
How a DNS Lookup Actually Happens
A single query for example.com passes through a short chain of servers before an answer comes back — none of which need to be told about each other in advance. Each one either knows the answer or knows who to ask next:
The path of a query
The answer then travels back down the same chain to the recursive resolver, which caches it for as long as that record's TTL allows before handing it to your device. Every later request for the same name is answered straight from that cache — nothing above the resolver gets asked again until the TTL expires.
Common Record Types
| Type | Name | Meaning |
|---|---|---|
| A | Host | Maps a domain to an IPv4 address. This is the most common record type and determines where a domain's website is hosted. |
| AAAA | Host (IPv6) | The IPv6 equivalent of an A record. |
| MX | Mail Exchanger | Mail exchange records. These specify which mail server or servers handle email for a domain, and in what priority order. This is the record most often misconfigured when email fails to arrive. |
| TXT | Text | Free-form text records used for verification and policy: domain ownership proof, SPF (which servers are authorized to send mail for this domain), DKIM keys, and various third-party service verification codes. |
| CNAME | Alias | An alias that points one hostname to another hostname rather than directly to an IP address. Commonly used for subdomains pointing at a hosting provider or CDN. |
| NS | Name Server | Name server records, which declare which DNS servers are authoritative for a domain — that is, which servers hold the actual records. |
Forward Lookup vs. Reverse Lookup
A forward lookup is the standard case: given a domain name, it returns the associated records (an A record's IP address, an MX record's mail server, and so on). A reverse lookup operates in the opposite direction: given an IP address, it returns the hostname (PTR record) associated with it. This is useful for identifying what a given IP address represents, and it is particularly relevant to mail server reputation — most receiving mail servers treat a missing or mismatched reverse DNS entry as a strong indicator of spam, and some reject the message outright.
Why MX Records Require Attention
Unlike an A record, a broken MX record often fails silently: there is no error page and no visible indication that anything is down. Mail simply stops arriving, or is rejected by the sending server with a bounce message the recipient never sees. Checking MX records after any domain or hosting change is an effective way to catch a mail outage before it results in undelivered correspondence going unnoticed.
Why TXT Records Matter
TXT records can appear to be arbitrary text, but they control meaningful functions: whether a mail server is authorized to send on a domain's behalf (SPF), whether outgoing mail is cryptographically signed (DKIM), and domain ownership verification for services such as Google Workspace, Microsoft 365, or CDN providers. Removing an unrecognized TXT record during cleanup is a common and avoidable cause of broken email deliverability or a lost service integration.
Why a Neutral Resolver Matters
DNS results can differ depending on which resolver answers a query — an ISP's resolver may have cached an outdated record, while a neutral public resolver returns the current one. Querying records from a neutral, server-side resolver avoids this ambiguity and reflects what the broader internet is currently seeing, rather than whatever is cached on a local machine.
If different resolvers appear to disagree after a recent change, a DNS Propagation checker is designed to detect that.
Frequently Asked Questions
Why does my domain have multiple MX records?
Redundancy and priority. Each MX record carries a priority number, and a sending mail server tries the lowest number first, falling back to the next if that server doesn't respond. Multiple records don't mean multiple copies of every email are delivered.
Why isn't my new DNS record showing up yet?
DNS results are cached according to each record's TTL (time to live) — a resolver won't re-check the authoritative servers until that TTL expires, even if the record already changed. A local machine's resolver may also be holding an older cached answer. Query a neutral resolver (what this tool does) rather than your own device, and use DNS Propagation checker to see which public resolvers have picked up the change.
What's the difference between A and CNAME records?
An A record points a hostname directly at an IPv4 address. A CNAME points a hostname at another hostname instead, which is then resolved in turn — commonly used for a subdomain pointing at a hosting provider or CDN endpoint rather than a fixed IP that provider might change.
Can a domain have both an A record and a CNAME on the same name?
No — this is a DNS protocol rule, not a limitation of this tool. A name with a CNAME record can't have any other record type at that same name. This is why CNAMEs are typically used on subdomains rather than the bare root domain.
Why would I run a reverse lookup instead of a forward lookup?
A reverse lookup answers a different question: given an IP address, what hostname is associated with it? This matters most for mail — most receiving servers treat a missing or mismatched reverse DNS entry (PTR record) on a sending IP as a spam signal, and some reject the message outright.
Use the DNS Lookup tool to query all record types at once, or to inspect a single type such as MX or TXT individually.