DNS, email and security
DNS (Domain Name System)
DNS is the internet's phone book: it turns a domain name into the addresses and settings that browsers and mail servers need to reach it.
What DNS means in practice
A domain's DNS records say where its website lives, where its email goes and which services may send mail for it. They are served by nameservers, which the domain owner chooses.
Changing a record can take a short while to reach everyone, because answers are cached.
Why it matters
Missing or wrong DNS records are behind most "my site or email is down" problems, and email records such as spf record and dmarc protect a domain from being faked.
Try it
- Domain Health Check Expiry date, transfer lock, DNS, SPF and DMARC email security, and blocklists for a .com.
- Hosting Stats Who runs the DNS for 167 million .com names, and who runs yours.
Related terms
- Nameserver A nameserver is a server that holds a domain's DNS records and answers questions about it. A domain lists at least two so one can fail.
- DNS provider A DNS provider is the company that runs the nameservers for a domain. It is often, but not always, the registrar or the web host.
- SPF record An SPF record is a DNS entry that lists the servers allowed to send email for a domain, so receivers can spot mail that is faked.