DIAGNOSTIC PLAYBOOK
A flattened SPF record is stale: recover provider coverage
A flattened SPF record can keep authorizing old IP addresses after a sending provider changes its infrastructure. The policy may remain syntactically valid while new legitimate messages fail.
HealthCheck Email editorial team · · Examples are illustrative
How to investigate
- Compare failing source IPs with the addresses in the flattened policy and the provider's current supported authorization.
- Find who owns the refresh process and when it last ran successfully.
- Restore a maintainable authorization configuration within the lookup budget, then test every active service.
What this looks like
ILLUSTRATIVE EXAMPLE
An address snapshot was generated months ago. The provider moves a mail stream to a new range, but the customer's static SPF record never changes.
A mistake to avoid
Removing every old address immediately can affect queued or alternate paths. Use provider guidance and recent traffic evidence to plan the transition.
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.