A CNAME (canonical name) record is a DNS entry that says one domain name is an alias of another. When a computer looks up links.yourbrand.com and finds a CNAME pointing to a service provider’s host name, it follows that pointer and uses whatever addresses the provider publishes. The provider can then change its servers without you editing your DNS.
Email platforms use CNAME records in a few places. Branded tracking domains are the most common: you point a subdomain such as links.yourbrand.com at the platform, so tracked links in your emails show your own domain instead of a shared one. Some platforms also use CNAMEs to publish DKIM keys or a custom return-path domain, which lets them rotate keys or manage bounce handling on your behalf.
There are a few rules to know. A CNAME can’t sit on your root domain (yourbrand.com itself) alongside other records, which is why platforms ask for a subdomain. A name that has a CNAME can’t also have other record types such as TXT or MX. And some DNS providers automatically append your domain to whatever you type in the host field, so entering “links.yourbrand.com” can create “links.yourbrand.com.yourbrand.com” by mistake.
DNS changes take time to spread, from minutes to a few hours depending on the TTL. If a check fails right after you add a record, wait and try again before changing anything. Online lookup tools that show exactly what a name resolves to are the quickest way to spot a typo or a duplicate record.
A Mumbai skincare brand wants its email links to show its own name. In its DNS panel it adds a CNAME with host “links” pointing to the host name its email platform provides. Within the hour, the platform verifies the record and links in new campaigns begin with links.brandname.in.
MailNesto uses a CNAME record for your branded tracking domain, checks it for you, and adds HTTPS to the domain automatically once the record is found.