What is DNS, and why does it affect my email and website?
DNS, the Domain Name System, is your domain's directory. Its records tell the internet which server shows your website and which service receives your email. Because both live in the same place, one wrong or missing record can take your site offline or stop mail arriving, even when nothing else has changed.
The short version
- DNS turns your domain name into the addresses of the services behind it.
- A and CNAME records point to your website; MX records point to your email.
- TXT records hold SPF, DMARC and verification codes. DKIM uses TXT or CNAME records, depending on your email provider (Microsoft 365 uses CNAME).
- Your nameservers decide where all those records are managed.
How does DNS work?
When someone types your web address or emails you, their device asks DNS where to go. The answer comes from your domain’s records, kept by whichever service your nameservers point to.
A handful of records do most of the work:
| Record | What it does |
|---|---|
| A | Points your domain to the server that hosts your website |
| CNAME | Points one name to another, often used for “www” |
| MX | Says which service receives your email, such as Microsoft 365 or Google Workspace |
| TXT | Holds text other services check, including SPF, DKIM, DMARC and verification codes |
Each record also has a TTL, which says how long other systems may remember it. That’s why changes don’t show up everywhere at once. See why DNS changes take time. The glossary covers DNS, A records and MX records.
Why does it matter?
DNS is the one place where your website and your email meet. A change meant for one can break the other:
- Replacing all records during a website move can delete the MX records, and email stops.
- Switching nameservers moves every record to a new provider. Anything not copied across stops working.
- Missing SPF or DKIM records push your mail into spam. See why business emails go to spam.
- An expired domain takes every record with it. See what happens when a domain expires.
Who controls my DNS?
Your registrar is where the domain is registered. Your nameservers decide where its DNS is managed: the registrar, your host, or a DNS service like Cloudflare. These can be three different companies. Know which is which, and make sure the business has its own login to each. Read who should own your domain.
What are the common mistakes?
- Editing records at the wrong company. If your nameservers point to Cloudflare, changes at the registrar do nothing.
- No copy of the records. Without one, nobody can put things back after a bad change.
- Old records left behind for services you no longer use.
- Logins held by a former web designer.
What if something stopped working after a change?
Compare the current records with your saved copy and put back anything missing. Then allow time for cached answers to expire. If you’re making a change now, read how to change DNS records without breaking email.
How much does it cost, and how long does it take?
DNS is usually included with your domain or hosting. Viewing records takes minutes. Changes are quick to make but can take from minutes to a day to reach everyone, depending on the TTL.
How does E-3 handle this?
We manage DNS for the websites and email we look after, and we save a copy of every record before touching anything. Adding records for a new service is one of the routine requests we handle; see how to add DNS records for a new service. To check your domain’s expiry and certificate, try the free domain and SSL checker.
Related questions
Common questions
- Where are my DNS records?
- Wherever your domain's nameservers point. That's often your registrar, but it may be your web host or a service like Cloudflare. A DNS lookup tool shows which.
- Is DNS the same as hosting?
- No. Hosting is where your website files live. DNS is the directory that sends visitors to that host and sends email to your email provider.
- Can I see my own DNS records?
- Yes. Log in where your nameservers point and open the DNS or zone settings. Public lookup tools also show most records.
Rather talk it through?
Call our team, or send a note and we’ll reply within one business day. No pressure and no jargon.