DNS Lookup:
Verify Your Domain's DNS Records
A domain migration ends. A new sender gets added. A record quietly goes stale. Sendmarc's DNS lookup tool checks every record published under a domain in seconds, so you can confirm your setup is correct and catch changes before they cause a problem.
Enter your company's domain below to get started.
What Is a DNS Lookup?
A DNS lookup queries the Domain Name System (DNS) to translate a domain name, such as sendmarc.com, into the IP address computers use to communicate.
IT administrators use a DNS lookup tool to validate records after a change. Security teams use it to investigate misconfigurations. Domain owners use it to confirm exactly what's published before handing off a migration.
Why DNS Lookups Matter
Checking DNS records is how you confirm a domain is configured the way you expect, not the way you assume it is.
DNS records show which email servers are authorized to send on a domain's behalf. That information is the starting point for setting up SPF, DKIM, and DMARC correctly.
A DNS lookup won't catch every risk on its own. Ongoing monitoring is what confirms your DNS stays accurate as your environment changes.
How a DNS Lookup Works
When someone enters a domain name into a browser, a series of queries resolves it to the correct IP address.
The process happens in a handful of steps:
- Request A user enters a domain name, triggering a request for its IP address.
- Recursive resolver The browser sends the query to a recursive DNS server, typically managed by the router or internet service provider (ISP).
- Cache check If the resolver already holds a recent record, it returns that result immediately.
- Root nameserver If nothing is cached, the resolver queries a root nameserver, which points to the correct top-level domain (TLD) nameserver.
- TLD nameserver The TLD server directs the resolver to the authoritative nameserver for the domain.
- Authoritative record The resolver requests the record from the authoritative nameserver, which returns the relevant data.
- Response The resolver caches the record and delivers the result to the user.
What Sendmarc’s DNS Lookup Tool Shows You
Enter any domain and get results across the following record types:
A/AAAA records
example.com · A · TTL 300
example.com · AAAA · TTL 300
example.com · MX · TTL 3600
example.com · MX · TTL 3600
TXT records
example.com · TXT · TTL 300
_dmarc.example.com · TXT · TTL 300
CNAME records
www.example.com · CNAME · TTL 300
mail.example.com · CNAME · TTL 300
NS records
example.com · NS · TTL 86400
example.com · NS · TTL 86400
SOA records
example.com · SOA · serial 2026100901 · refresh 7200
CAA records
example.com · CAA · TTL 3600
example.com · CAA · TTL 3600
SRV records
_sip._tcp.example.com · SRV · TTL 3600
How to Use Sendmarc's DNS Lookup Tool
- Enter the domain. Type the domain you want to check into the lookup tool.
- Select Lookup. The tool queries the DNS directly and returns live results.
- Review the records. Check which record types are published and confirm they match what you expect.
- Act on it. Fix a misconfiguration, confirm a migration completed correctly, or flag an unexpected record for further investigation.
Once you know what's published under a domain, spotting an unexpected record or a leftover entry becomes easy. Run a DNS lookup after any change, rather than assuming it went as planned.
Check DNS recordDNS Lookup FAQs
What is DNS lookup used for?
DNS lookup is used to translate human-readable domain names into IP addresses. A DNS lookup retrieves the DNS records needed for a website or domain to function correctly.
How do you look up a DNS name?
You can look up a DNS name by using a tool like Sendmarc’s DNS lookup tool to query DNS servers directly. A DNS lookup retrieves the records linked to a domain, providing insight into how it's configured.
How does DNS lookup work?
DNS lookup works by sending queries through a chain of DNS servers - including root, TLD, and authoritative servers - to resolve a domain name into its IP address and associated records.
What types of records can I check with a DNS lookup?
A DNS lookup can retrieve multiple record types, including A, AAAA, MX, TXT, CNAME, NS, SOA, CAA, and SRV records. These records provide different details about how a domain is configured.
Why would a DNS lookup show incorrect or missing records?
A DNS lookup can show incorrect or missing records because of recent DNS changes that haven't fully propagated, typos in the DNS configuration, or records that were never published. Checking regularly helps catch these issues before they affect email delivery.
Is a DNS lookup the same as checking DMARC compliance?
No, a DNS lookup is not the same as checking DMARC compliance. A DNS lookup shows which records exist on a domain, while DMARC compliance depends on whether SPF, DKIM, and DMARC records are correctly configured and aligned, and whether the policy is enforced.
How often should I run a DNS lookup?
Run a DNS lookup after any DNS change, domain migration, or new sender addition, and periodically as part of routine domain monitoring. Enterprises managing multiple domains benefit from continuous monitoring rather than one-off checks.