SPF Flattening
SPF flattening replaces include chains with IP literals to reduce DNS lookups. Static flattening can go stale when vendor IPs change—prefer maintained automation when possible.
Why people flatten
Nested includes from M365, Google, and multiple ESPs frequently exceed the RFC 7208 limit of 10 DNS-causing mechanisms.
Risks of naive flattening
Hard-coded IPs drift. When a vendor adds ranges, your flattened record silently fails authorized mail.
Better patterns
Remove unused includes, send marketing from subdomains, and use managed SPF (QuickSPF) that updates includes safely.
How QuickDMARC helps
QuickSPF is designed to solve lookup overages without brittle one-time flattening spreadsheets.
Frequently asked questions
Is flattening required?
Only if you cannot stay under 10 lookups with cleaner architecture.
Does flattening replace DMARC?
No. Flattening is an SPF maintenance technique.
Related problem page?
See SPF too many DNS lookups.