Every time someone types your domain into a browser, sends you an email, or verifies your identity with a third-party service, DNS records decide what happens next. Understanding the four record types you will meet most often makes it far easier to diagnose problems and to tell us exactly what you need changed.
A record
An A record points a hostname at an IPv4 address. It answers the question "which server hosts this site?"
Example: example.com → 203.0.113.10
If your website has moved to a new server and visitors still land on the old one, an A record that has not been updated is the usual cause. The equivalent record for IPv6 addresses is called AAAA and works identically.
CNAME record
A CNAME points one hostname at another hostname rather than at an IP address. It is an alias.
Example: www.example.com → example.com
The advantage is that if the underlying address changes, you only update it in one place. The important limitation is that you cannot put a CNAME on the root of your domain alongside other records — that is why www can be a CNAME but the bare domain usually needs an A record.
MX record
MX records tell the world which servers accept email for your domain. They carry a priority number, and lower numbers are tried first.
This is the record that matters when email stops arriving. A common and painful mistake is moving a website to a new host and letting the migration overwrite the MX records, which silently redirects mail to a server that is not expecting it.
If you change hosting providers, always confirm your MX records separately from your website records.
TXT record
TXT records hold arbitrary text, and in practice they are used to prove that you control a domain. Three uses matter most:
- SPF — lists which servers are allowed to send email as your domain
- DKIM — publishes the key used to cryptographically sign your outgoing mail
- DMARC — tells receiving servers what to do when a message fails SPF or DKIM
Together these three are what stop other people spoofing your domain, and they are among the first things worth checking if your legitimate email is landing in spam folders.
Why changes are not instant
Every record carries a TTL, or time to live, measured in seconds. This tells other servers how long they may cache the answer before asking again. A record with a TTL of 3600 can take up to an hour to update everywhere, and some networks hold results longer than they should.
If you know a change is coming, lowering the TTL a day beforehand shortens the switchover window considerably.
Getting a record changed
Open a ticket telling us the domain, the record type, the exact value you need, and when the change needs to take effect. If you are migrating a service, mention that too — it lets us check your mail records at the same time and avoid the outage described above.
