SPF Flattener
Resolve nested includes into flat IP lists to reduce DNS lookups
3 min read
Tools
SPF Flatten
Resolves all nested include: directives in an SPF record into a flat list of IP addresses.
Why Flatten?
SPF has a 10 DNS lookup limit. Each include: counts as a lookup, but ip4: and ip6: mechanisms do not. Flattening converts includes into direct IP addresses, reducing your lookup count.
Output
- Flattened SPF record with all IPs resolved
- Lookup count before and after flattening
Warning: Flattened records break when source IPs change. Only use flattened records if you have a process to keep them updated.
Tip: DMARC Busta's managed SPF handles lookup optimization automatically. Use this tool for analysis, not production records.