SPF flattening tools
An SPF flattening tool resolves your record’s includes to raw IPs so you stay under the 10-lookup limit. The important distinction is between a one-off flattener and a managed, self-healing service that keeps the record correct over time.
What an SPF flattening tool does
- Expands every
include/a/mxrecursively to its leaf IP ranges. - Counts your DNS lookups and flags when you exceed 10.
- De-duplicates overlapping ranges across all your senders.
- Produces a compact record that authorizes the same senders in far fewer (or zero) lookups.
Why a one-off flatten isn’t enough
A static flattened record is correct only until a provider changes its IPs. After that, mail from the new IPs fails SPF and you won’t know until deliverability drops. A one-off tool hands you a record and walks away; keeping it accurate becomes your job, forever.
What to look for in a managed service
- Continuous monitoring & auto-updates — the record re-flattens when upstream providers change, so it never goes stale.
- Single-lookup result — ideally a macro
(
exists) or a hosted include that costs one lookup regardless of how many senders you have. - Preserves DMARC alignment — the mechanism still evaluates on your domain.
- Change alerts — you’re told when senders are added or removed.
- You edit DNS once — a single record change, then it’s hands-off.
Our recommendation
For anything beyond a one-time prune, use a managed, self-healing record rather than a static flatten. The most robust option we’ve tested delivers a single-lookup, macro-based record that stays in sync automatically — you get the benefit of flattening without the maintenance risk. Start by checking your current record: