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SPF Flattening Tool
SPF allows at most 10 DNS lookups, and every include counts - with it exceeded, SPF fails and your mail loses its pass. Enter your domain, choose which includes to replace with their IP addresses, and get a record that fits, split into sub-records automatically when it’s too long.
What this does - and doesn’t - tell you
What it does
- Follows every include, redirect, a and mx term in your SPF record and counts the real DNS lookups each costs.
- Replaces the ones you choose with the ip4 and ip6 ranges they resolve to, and recounts the lookups.
- Splits the addresses across sub-record includes when a single record would be too long for one DNS answer.
Worth knowing
- Flattening is a trade-off, not a free fix. The addresses are a snapshot. When a provider changes its IPs your record doesn’t follow, and mail from them fails SPF without any error you’ll see.
- Try the alternatives first: remove senders you no longer use, and move bulk senders to a subdomain with its own SPF record.
existsandptrterms can’t be flattened. This tool changes nothing in your DNS - you publish the record yourself.- Need to see the problem first? The SPF Record Checker shows the lookup count and the include tree.
Hitting the SPF limit usually means too many sending services on one domain. We restructure the sending setup so SPF stays valid without a record you have to keep re-flattening.
How we help: Consulting · Private infrastructure · Managed mailboxes · Monthly support