DNS connects your domain name to the services that use it, including your website, business email, verification tools, and subdomains. This guide explains the main DNS records, shows how to plan and check them, and gives you a repeatable troubleshooting routine whenever your hosting or email setup changes.
Overview
DNS, or the Domain Name System, acts like a directory for the internet. When someone enters your domain, DNS helps their browser find the server hosting your website. When someone sends email to you, mail servers use DNS to find the correct email provider.
Your domain is usually registered with a domain registrar, while DNS may be managed at the registrar, your hosting company, or a separate DNS provider. These services can be operated by different companies. That is why the first step in any DNS task is to identify where the domain’s authoritative nameservers point. The dashboard where you bought the domain is not necessarily the dashboard where you should add records.
Before making changes, record your current settings. Copy the existing values into a simple document or spreadsheet, including the record type, host or name, value, TTL, purpose, and date checked. This small habit makes it easier to reverse a mistake and identify which service owns each entry.
For a broader launch process, use the Website Launch Checklist for a professional small business site. If you are specifically connecting a new domain to hosting, see How to Connect a Domain to Web Hosting.
What to track
DNS dashboards use slightly different labels. One provider may call the first field “Name,” another may call it “Host,” and some automatically append your domain. Focus on the record type and the complete result rather than copying a dashboard label word for word.
A and AAAA records: sending visitors to your website
An A record maps a hostname to an IPv4 address. A common example is an entry for the root domain, sometimes shown as @, pointing to the IPv4 address supplied by your hosting provider. An AAAA record performs a similar job for an IPv6 address.
Use the exact address provided by your host. Do not guess it from an old setup or copy an address from an unrelated server. If your hosting provider gives you both an A and an AAAA record, add both as instructed. If you are moving hosts, check for old records that still point to the previous server.
CNAME records: aliases and subdomains
A CNAME record points one hostname to another hostname rather than directly to an IP address. It is commonly used for www, landing pages, website platforms, or services that ask you to create a subdomain such as blog, shop, or app.
For example, a provider might instruct you to set the host to www and the target to a provider-owned hostname. Follow the provider’s supplied target exactly. Avoid creating a CNAME and an A record for the same hostname unless the service documentation explicitly explains a special configuration.
MX records: delivering business email
MX records tell sending mail servers where to deliver email for your domain. Your email provider normally supplies one or more mail-server hostnames and a priority value. If there are multiple MX records, the priority determines the preferred delivery route; the lower number is commonly treated as higher priority, but follow the instructions in your provider’s setup screen.
When changing email providers, do not delete the existing MX records until you are ready to switch delivery. At the cutover, remove obsolete MX records and add the complete set required by the new provider. Leaving old and new records together can produce inconsistent delivery.
TXT records: verification, SPF, and other instructions
TXT records store text used for domain verification and email authentication. A website platform may ask you to add a TXT value to prove domain ownership. An email provider may request an SPF record, which is also published as TXT, to identify permitted sending services.
Only publish an SPF policy supplied or approved by the email provider. A domain should have one coherent SPF record rather than several separate SPF records. If several services send mail for your domain, combine their approved mechanisms according to the providers’ instructions instead of adding unrelated TXT entries.
Other email authentication records may include DKIM and DMARC. These are also commonly provided as DNS instructions, often using a specific hostname such as a selector for DKIM. Copy long values carefully, keep quotation marks only when the DNS interface requires them, and check whether the provider expects a trailing dot on a hostname.
NS records: identifying the DNS manager
NS records identify the nameservers responsible for a domain’s DNS. You may not edit them in the same record table as A, CNAME, or MX records. Nameservers are usually changed at the registrar, while the individual DNS records are then managed at the selected DNS provider.
Changing nameservers can move control of all DNS records at once. Before doing so, recreate essential website, email, verification, and subdomain records in the new DNS account. Otherwise, a nameserver change can make a working website or email service appear to stop.
A practical record-planning template
Keep a record like this for each domain:
| Type | Host/name | Value or target | Purpose | Provider | Checked |
|---|---|---|---|---|---|
| A | @ | Hosting IPv4 address | Root website | Web host | Date |
| CNAME | www | Hosting target | WWW version | Web host | Date |
| MX | @ | Mail-server hostname | Business email | Email provider | Date |
| TXT | @ or specified host | Verification or SPF value | Ownership or email authentication | Relevant provider | Date |
Cadence and checkpoints
DNS usually does not need daily attention. A monthly or quarterly review is sufficient for many small sites, with an additional check whenever a service changes. The goal is not to edit records routinely; it is to notice ownership, expiration, and configuration changes before they become an outage.
- Monthly: Confirm that the website loads at the root domain and the
wwwversion, email can be sent and received, and your DNS account remains accessible. - Quarterly: Compare the live records with your record-planning document. Remove entries for services you no longer use, but verify their purpose before deletion.
- Before a hosting migration: Record the current zone, lower TTL only if your provider recommends it, and prepare the new website records before switching traffic.
- Before an email migration: Collect the new MX, SPF, DKIM, and any verification records. Plan the change and test mail delivery after the cutover.
- After any change: Note the exact time, the old value, the new value, and the service affected. Check from more than one network or use a DNS lookup tool to compare results.
DNS updates are not always visible everywhere immediately. A propagation tracker should include the time of the change, the expected TTL, lookup results from several locations, and a final confirmation from the service you are configuring. Treat a provider’s setup status as one signal, not the only test.
How to interpret changes
If the website works on one hostname but not another, compare the records for the root domain and www. A missing CNAME, an incorrect A record, or two conflicting records may explain the difference. If the site displays an old version, confirm that the new hosting address is correct before assuming the issue is browser or server caching.
If email stops arriving, inspect MX records first. Confirm that the domain uses the intended mail provider and that old MX entries have been removed when appropriate. If messages are sent but not trusted, review the provider’s SPF and DKIM instructions. DNS changes alone cannot correct every email problem, so also check the mailbox, sending service, and provider status.
If a verification service cannot find a TXT or CNAME record, check the host field carefully. Some dashboards expect only the label, while others expect the full hostname. Also check for accidental spaces, duplicate records, a value entered in the wrong field, or a record added at the wrong DNS provider.
For a basic troubleshooting sequence, follow this order:
- Confirm which nameservers are authoritative.
- Confirm the record exists in that provider’s dashboard.
- Compare the hostname and value with the service’s instructions.
- Check for conflicting records or obsolete entries.
- Allow for caching and propagation, then test again.
- Contact the affected provider with the timestamp and lookup results if the issue remains.
When to revisit
Revisit this DNS reference at least quarterly and whenever you renew, move, add, or remove a connected service. The most important triggers are a hosting migration, an email-provider change, a new landing-page platform, a new subdomain, a change to business email senders, or a nameserver update.
Set a calendar reminder to review your record inventory. During that review, confirm the website, email, SSL-enabled versions of the domain, important subdomains, and domain verification records. Update the purpose and owner of each record so the next change does not depend on guesswork.
When you are ready to launch or migrate, pair this process with the small business website launch checklist. For ongoing WordPress sites, the WordPress maintenance checklist can help you track related security, performance, and SEO checks. A short, dated DNS inventory turns a confusing technical task into a manageable recurring routine.
