The main DNS record types explained
An A record maps a domain name to an IPv4 address. It's the most fundamental record: example.com → 93.184.216.34. The AAAA record does the same for IPv6 addresses. Most domains have both.
A CNAME (Canonical Name) record maps one domain name to another. www.example.com CNAME → example.com means that www is an alias for the root domain. CNAMEs can't coexist with other records at the same hostname, which is why many DNS providers support ALIAS or ANAME records as a CNAME workaround for the root domain.
MX (Mail Exchanger) records specify which servers handle email for the domain. They have a priority value — lower numbers have higher priority. Multiple MX records provide redundancy. If you're troubleshooting email delivery, MX records are the first place to look.
- A — maps domain to IPv4 address
- AAAA — maps domain to IPv6 address
- CNAME — alias from one domain to another
- MX — mail server for the domain
- TXT — arbitrary text, used for SPF, DKIM, domain verification
- NS — nameservers authoritative for the domain
- SOA — start of authority, primary nameserver info
- SRV — service location records (VoIP, XMPP, etc.)
- CAA — certificate authority authorization
TXT records and what they're used for
TXT records store arbitrary text data associated with a domain. Their main use today is for email authentication and domain verification.
SPF (Sender Policy Framework) TXT records specify which servers are authorized to send email for the domain. DKIM TXT records publish the public key used to verify email signatures. DMARC TXT records set the policy for how recipients should handle email that fails SPF or DKIM checks. Together, these three records protect against email spoofing.
Domain verification records are also stored as TXT records. Google Search Console, AWS, and many SaaS tools ask you to add a specific TXT record to prove you control the domain.
Diagnosing DNS problems
The most common DNS issue is propagation delay. When you change a DNS record, the old record stays cached for up to 48 hours (the TTL — Time to Live value). During propagation, some users may see the old record and others the new one. You can reduce future propagation time by lowering TTL values before making changes.
Using the Irreva DNS Lookup tool, you can query a specific record type for any domain and see the current value. Compare what the DNS lookup returns against what you've configured in your registrar's DNS panel. Discrepancies point to propagation delays or misconfiguration.
For email delivery problems, check MX records, then TXT records for SPF/DKIM/DMARC. A missing or incorrect SPF record is the most common cause of legitimate email landing in spam.