The Domain Name System is the internet’s directory. For each domain it holds records that tell other computers where things are: which server hosts your website, which servers receive your email, and which services may send email in your name. You manage these records in a DNS panel, usually at your domain registrar or a DNS host.
Email relies on several record types. MX records say where incoming email for your domain should go. TXT records carry SPF (who may send for you), DKIM public keys and DMARC policies. CNAME records create aliases, often for branded tracking domains. PTR records, set by whoever controls an IP address, map that IP back to a host name. Together they decide whether receivers trust mail that claims to come from you.
Most DNS mistakes in email come from a few habits. Adding a second SPF record instead of editing the existing one breaks SPF. Pasting a DKIM key with a missing character fails silently. Deleting an old record you don’t recognise can stop invoices or office email. Before editing, take a screenshot of the existing records, change one thing at a time and test it.
Changes are not instant. Each record has a TTL (time to live) that tells other servers how long to cache it, so an update can take minutes or a few hours to be seen everywhere. If a verification check fails straight after you make a change, waiting is usually the right move.
A Thane architecture firm uses Google Workspace for staff email and an email platform for newsletters. Its DNS holds MX records pointing to Google, one SPF record that includes both Google and the platform, two DKIM keys with different selectors, a DMARC record and a CNAME for its tracking domain.
MailNesto shows the DNS records to add for each sending domain and checks DKIM, SPF, DMARC and MX live, flagging problems such as more than one SPF record.