DIAGNOSTIC PLAYBOOK
SPF macros: inspect the name that gets queried
SPF macros construct domain names from evaluation inputs such as the sender or IP address. A literal record inspection cannot tell you the final DNS name without the corresponding message context.
HealthCheck Email editorial team · · Examples are illustrative
How to investigate
- Record the exact IP, envelope sender and HELO identity used by the receiver.
- Expand the macro according to the SPF specification and inspect the resulting name, including length and escaping.
- Resolve that name and ask the policy operator to investigate missing or malformed responses.
What this looks like
ILLUSTRATIVE EXAMPLE
A provider uses exists with an IP-dependent macro. Two sending IPs produce different query names, so one successful manual lookup does not test both paths.
A mistake to avoid
Do not rewrite a provider's macro as a static address based on one sample. The dynamic behavior may be essential to its authorization model.
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.