Start with the sending setup
Identify the domain and email provider before changing DNS. MX records identify receiving mail servers. SPF publishes sender authorization rules. DKIM uses selector-specific public keys, while DMARC describes handling and reporting for aligned authentication results.
Know what a DNS check proves
A found record confirms that a lookup returned data. It does not confirm that a particular message passed SPF, had a valid DKIM signature or reached the inbox. Use message headers and provider delivery logs for those questions.
Supply the DKIM selector
A domain can use several selectors. Obtain the selector from your mail provider or a message signature and check that exact name. An absent result for one selector says nothing about other selectors. Review duplicate SPF or DMARC records before adding another one.
Example
Illustrative publication review MX: found SPF: found DKIM: selector not supplied — not checked DMARC: found Conclusion: inspect authentication results on an actual message.
What to check next
- Run Email DNS Health with the domain and provider-supplied DKIM selector.
- Use DNS Lookup for the returned MX and TXT records.
- If answers differ, compare resolvers. For delivery problems, inspect the sending IP and message authentication results separately.