How to Check Whether an SPF Include Creates a DNS Lookup Loop

An SPF policy can fail when an included domain points back to the original policy, creates a loop, or adds too many nested DNS lookups. A visible SPF record may look simple while its included services expand into a complex chain.

Trace the include chain

List each include, redirect, and nested mechanism. Confirm that every service is still used and that the provider's record is current. Keep one policy for the domain and avoid adding broad authorization as a workaround.

• Use a DNS-aware SPF evaluator and verify the authoritative record.
• Remove obsolete senders only after confirming they no longer send mail.
• Consolidate policy entries according to provider guidance.
• Test legitimate outbound mail and review authentication results.

Informatix Systems lists DNS and business email services. A review can help map SPF, DKIM, and DMARC senders. Contact Informatix Systems if SPF checks fail unexpectedly.