Understanding DNS Records: A Plain-English Guide for Everyone

PGW
5 days ago
3 min read

A perplexed office worker stares at his computer, surrounded by DNS terms like CNAME, MX, SFX, and DKIM, illustrating the challenges of managing complex digital tasks.

If you own a website, you’ve probably heard of DNS records, but what do they actually mean? Think of DNS as the address book of the internet: it tells browsers and email servers where to find your website, your email inbox, and other services connected to your domain.

Here’s a breakdown of the most common DNS records you might see when managing yourdomain.co.uk (or any other domain):

🔑 Core Records

SOA (Start of Authority)

Defines the main server that holds the “authoritative” DNS zone for your domain. It includes admin contact details, a version number (serial), and timing rules for how often other DNS servers should check for updates.
NS (Name Server)

These point to the DNS servers responsible for your domain. Example: ns1.yourhost.com, ns2.yourhost.com. If you move hosting, you usually need to update these.
A Record

Maps your domain name to an IP address. Example: yourdomain.co.uk → 192.0.2.123. This is what makes your website load when people type in your domain.
CNAME (Canonical Name)

An alias that points one name to another. Example: www.yourdomain.co.uk → yourdomain.co.uk. Useful to avoid duplicating IP addresses.

📧 Email & Authentication

MX (Mail Exchange)

Directs incoming mail to the server that handles your email. Example: MX → mail.yourdomain.co.uk.
SPF (TXT Record)

Specifies which servers are allowed to send email for your domain. Helps reduce spam and spoofing.
DKIM (TXT/CNAME Records)

Provides a cryptographic signature to prove that emails really come from your domain. Essential for modern email deliverability.
DMARC (TXT Record) (not always set up, but recommended)

Works alongside SPF and DKIM to instruct receiving servers what to do if an email fails authentication.
Third-Party Email Services (e.g., SendGrid, Microsoft 365, Google Workspace)

When using an external email provider, you’ll often see unique CNAMEs (like em1234.yourdomain.co.uk) or special DKIM records. These are unique to each account and must match exactly to verify your domain.

Diagram illustrating a DNS zone managing connectivity between a website server, email server, and third-party provider.

🌐 Hosting & Control Panel

If your domain uses cPanel or similar hosting, you may see records like:

ftp.yourdomain.co.uk → IP address (for FTP access)
cpanel.yourdomain.co.uk → IP address (for hosting control panel)
webmail.yourdomain.co.uk → IP address (for webmail login)

These all point to the same server but give convenient shortcuts.

📅 Calendars & Contacts

Records such as caldav, carddav, and related SRV/TXT entries allow email and calendar apps (like Outlook or Apple Mail) to automatically sync contacts and calendar data with your hosting server.

🔒 Verification & SSL Certificates

_acme-challenge (TXT Record)

Used by Let’s Encrypt to issue SSL certificates.
_cpanel-dcv-test-record (TXT Record)

Used by cPanel to verify domain control during SSL setup.

These are temporary or technical records that prove you own the domain when setting up HTTPS.

✅ Key Takeaways

A/NS/MX → Core website and email functionality.
SPF/DKIM/DMARC → Email authentication and security.
CNAMEs → Aliases and third-party service verification.
SRV/TXT for calendars, SSL, etc. → Extra services and security.

💡 Common Pitfall

If you authenticate your domain with a third-party service (like SendGrid for email), they’ll give you specific CNAME and DKIM records. These are unique to your account. If you see a mismatch (for example, one set from an old provider and another from your new provider), email may fail until the old records are removed.

Final Word

DNS can seem complicated, but once you know what each record type does, it’s easier to spot problems and keep your domain running smoothly. Think of it like a control panel: A and CNAME point your website, MX handles email, and TXT/CNAME records verify trust.

With the right DNS setup, your website, email, and online tools all connect seamlessly.