SPF Flattener & Lookup Counter

SPF allows a maximum of 10 DNS lookups per evaluation. Every include: costs a lookup - and worse, each included record has its own includes, so one include:_spf.google.com can quietly consume four lookups. Stack a few providers and you blow past 10, which turns your entire SPF record into a PermError.

This tool resolves your SPF record including nested includes, counts the true lookup total, and shows where the budget is going so you can decide what to remove, replace with a direct IP, or flatten.

Flattening replaces include: mechanisms with the underlying IP addresses (ip4: and ip6:), which cost zero lookups - so a record that was failing at 14 lookups can drop to well under the limit. It's the most direct fix when you genuinely need many senders.

The catch is maintenance. Providers change their sending IPs periodically, and a flattened record is a frozen snapshot - if Google or your ESP rotates IPs and your flattened record doesn't follow, legitimate mail starts failing SPF. Only flatten what you must, and revisit flattened records on a schedule.

Before flattening, try the cheaper fixes. Remove unused includes - audit every include: and drop any service you no longer send through. Replace small fixed-IP senders with direct ip4: entries, which cost nothing. Consolidate overlapping providers where you can.

The cleanest structural fix is subdomains: send different email types (marketing, transactional, cold outreach) from separate subdomains, each with its own SPF record and its own fresh 10-lookup budget. That often removes the pressure entirely without freezing any IPs.