DNS records explained simply: A, AAAA, CNAME, MX and TXT
What do the DNS records of your domain mean? A, AAAA, CNAME, MX, TXT, SPF, DKIM and TTL explained in plain terms, with practical examples from everyday use.
The Domain Name System (DNS) translates names such as your-company.ch into the addresses that computers work with. Every domain has a zone with records that determine where website requests and emails go.
A and AAAA – where is the website?
An A record points to an IPv4 address (for example 203.0.113.10), an AAAA record to an IPv6 address. These two records determine which server your website is on.
CNAME – one name points to another
With a CNAME, you point a subdomain to another name, for example www.your-company.ch to your-company.ch. If the address of the target changes, all CNAMEs follow automatically.
MX – where do the emails go?
MX records determine which server accepts emails for your domain. The number in front is the priority: the server with the lowest number is tried first.
TXT – verification and protection against abuse
- SPF defines which servers are allowed to send emails on behalf of your domain.
- DKIM signs outgoing emails so that recipients can verify they are genuine.
- DMARC tells recipients how to handle emails that fail SPF or DKIM.
- In addition, many services (e.g. Google or Microsoft) use a TXT record to confirm that you own the domain.
Tip: SPF, DKIM and DMARC are now essential for reliable delivery – without them, your emails quickly end up in spam.
TTL – how long is it cached?
Every record has a TTL in seconds. It determines how long other servers may cache the answer. A short TTL speeds up changes, a longer one reduces queries. Before planned changes, it is worth lowering the TTL temporarily.
With our WHOIS lookup, you can see which registrar a domain is with and which name servers are set.
Frequently asked questions on this topic
That depends on the TTL of the record. With a TTL of 300 seconds, the change is usually visible within a few minutes; with 86,400 seconds, it can take up to a day.
An A record points directly to an IP address, a CNAME refers to another name. An A record is usually used for the main domain, and a CNAME is often used for subdomains.
One MX record is enough if your mail server is reliably reachable. Additional MX records with higher numbers act as backup mail servers.
