SPF Record Analyzer Form
Example Data Table
| Domain | Original SPF | Lookup Terms | Flattened Preview | Status |
|---|---|---|---|---|
| mail.alpha.test | v=spf1 include:_spf.alpha.test ip4:198.51.100.22 ~all | 1 | v=spf1 ip4:198.51.100.22 ip4:198.51.100.80 ~all | Ready |
| ops.bravo.test | v=spf1 a mx include:_spf.bravo.test -all | 3 | v=spf1 ip4:203.0.113.5 ip4:203.0.113.8 ip4:203.0.113.9 -all | Caution |
| alerts.charlie.test | v=spf1 exists:%{i}.spf.charlie.test include:_spf.charlie.test ~all | 2 | v=spf1 ip4:192.0.2.44 exists:%{i}.spf.charlie.test ~all | Needs Review |
Formula Used
Lookup-Triggering Terms = count(include + a + mx + exists + ptr + redirect) discovered during recursive parsing.
Flattened SPF = v=spf1 + all collected ip4: and ip6: terms + optional preserved non-static terms + final policy.
TXT Chunk Estimate = ceil(flattened_length / 255). This estimates how many TXT string segments may be needed in DNS.
Status Logic marks Ready for clean results, Caution for warnings, and Needs Review when critical errors remain.
How to Use This Calculator
- Enter a domain, paste an SPF record, or provide both.
- Choose recursion depth and terminal policy handling.
- Enable A and MX expansion when static IP collection is required.
- Decide whether unsupported mechanisms should remain in the output.
- Submit the form to generate the flattened record.
- Review lookup counts, warnings, output length, and preserved mechanisms.
- Export the analysis using the CSV or PDF buttons.
- Publish only after validating the final record in your DNS workflow.
Frequently Asked Questions
1. What does SPF flattening do?
SPF flattening converts recursive include, A, or MX logic into more direct IP-based terms. It helps reduce lookup overhead and makes sender authorization easier to audit and publish.
2. Why do lookup counts matter?
SPF processing has practical lookup limits. When too many lookup-triggering terms appear, receivers may stop evaluation early, which can break mail authentication and hurt deliverability.
3. Can every SPF mechanism be flattened safely?
No. Mechanisms like exists, ptr, and some macro-based logic are not safely reducible into static IP terms. Those are usually preserved or flagged for manual review.
4. Should I expand A and MX mechanisms?
Expand them when you want a more static record and trust the current DNS state. Keep them unexpanded when infrastructure changes often or when you prefer DNS-driven updates.
5. Why does record length matter?
Very long SPF strings are harder to manage and may require TXT splitting. Excessively large records also increase operational risk when teams update DNS manually.
6. What terminal policy should I use?
Use auto when you want the discovered policy preserved. Choose -all for strict rejection, ~all for soft failure, or ?all when you need a neutral outcome.
7. Does flattening remove the need for validation?
No. You should still validate the final policy with your DNS, mail platform, and staging tests. Flattening reduces complexity, but deployment mistakes can still block legitimate senders.
8. When should I avoid flattening?
Avoid aggressive flattening when sender IPs change frequently, vendor includes rotate often, or your mail program depends on dynamic DNS logic that a static list cannot mirror reliably.