DIAGNOSTIC PLAYBOOK
SPF none: find which domain was actually checked
SPF none means no applicable SPF policy was found, or no suitable domain identity was available for the check. The first useful question is which identity the receiver evaluated, not whether your website domain has a TXT record.
HealthCheck Email editorial team · · Examples are illustrative
How to investigate
- Read smtp.mailfrom and smtp.helo in the receiver's authentication results where available.
- Look up TXT records on that exact domain, including any bounce subdomain.
- Compare the sending service's custom return-path configuration with the identity in the message.
What this looks like
ILLUSTRATIVE EXAMPLE
Your root domain has SPF, but the message uses bounce.mail.example as its envelope domain. The root policy is not inherited by that subdomain.
A mistake to avoid
Publishing SPF at the apex does not automatically authorize every subdomain. Avoid adding unrelated records until you identify the evaluated name.
Keep the result in context
SPF evaluates the SMTP client against the envelope sender domain, or the HELO identity in the applicable case. A record lookup can identify publication problems; a message result also needs the actual sending IP and identity. Keep those inputs with your investigation.
Take the next step
Use the related check to gather evidence, then compare it with the affected message or service. Keep the result and time with your notes so a later change can be distinguished from the original problem.
Sources and further reading
The protocol references below explain the underlying behavior. Your sending or DNS provider supplies the account-specific settings for its service.