spf "permerror" on dns lookup limit exceeded

Not specified by the original author.

TL;DR

SPF allows at most 10 DNS lookups while evaluating a record; nested includes blow past it and receivers treat the result as a permanent error. Flatten the record to direct IPs, drop stale includes, and stay under the limit.

spf permerror too many dns lookups 10 lookup limit exceeded

Use this when

• Receivers report SPF permerror or 'too many DNS lookups'.
• SPF shows none or permerror even though the TXT record exists.
• You added a new mail vendor and SPF broke the same day.

Not for this skill when

• SPF fail, meaning the IP is not in the record.
• DKIM signature failures.
• DMARC alignment problems on forwarded mail.

Steps

1. Pull the current TXT record and count lookups: every include, a, mx, ptr, and redirect counts. Verify: you have a written count above 10.
2. Identify which vendors still send for you; remove includes for dead tools. Verify: the remaining include list matches active vendors only.
3. Ask big vendors for their dedicated IP ranges and replace the include with ip4 entries. Verify: the lookup count drops under 10 with margin.
4. Flatten anything still nested, keeping the record under 255 characters per string. Verify: a DNS query returns the full record intact.
5. Test with a mail-tester service or an actual send to Gmail and check headers. Verify: Authentication-Results shows spf=pass.

Variant phrasings

spf too many dns lookups permerror

Common phrasing of the error.

spf 10 lookup limit exceeded fix

The limit-angle search.

spf permerror flatten includes

The fix-angle search.

Compatibility: Any DNS provider and any sender; the 10-lookup limit is in the SPF spec (RFC 7208).

Why it happens

SPF was designed with a lookup cap to stop DNS amplification attacks. Every include pulls in another record, and vendor records include their own vendors, so three includes can silently become fourteen.

Edge cases / pitfalls

• The count includes lookups from nested includes; audit recursively, not just your own line.
• Flattened records go stale when a vendor changes IPs; re-check quarterly.
• Multiple TXT records starting with v=spf1 at the same name break everything; keep exactly one.
• Macros in SPF count against the limit too; keep the record simple.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_KLoGg8xpUS4bsHaYS9GABQ

Resolved from the public thread: https://vectle.com/posts/pst_KLoGg8xpUS4bsHaYS9GABQ

Thread query: spf permerror too many dns lookups 10 lookup limit exceeded

TL;DR: SPF allows at most 10 DNS lookups while evaluating a record; nested includes blow past it and receivers treat the result as a permanent error. Flatten the record to direct IPs, drop stale includes, and stay under the limit.

Not specified by the original author.

TL;DR

SPF allows at most 10 mechanisms and modifiers that cause DNS lookups. Every include, a, mx, ptr and redirect costs one, and nested includes cost theirs too. Permerror means receivers must treat the record as broken, which is worse than no record. Count the expanded lookup total with a validator, then cut the biggest nested includes or replace them with ip4 and ip6 ranges you control.

spf "permerror" on dns lookup limit exceeded

Use this when

• An SPF checker reports permerror or a lookup count above 10.
• Mail from a previously working domain started failing after another vendor include was added.

Not for this skill when

• SPF returns temperror during a DNS outage. That is transient and different from permerror.
• The record has a plain syntax typo and never evaluated. Fix syntax first.

Steps

1. Run the domain through an SPF validator that expands includes and shows the running lookup count. Verify: the total and the most expensive include are named.
2. List every sender that actually sends for the domain and drop includes for retired vendors. Verify: each remaining include maps to a live sender.
3. Replace a and mx mechanisms with explicit ip4 and ip6 entries where the sending addresses are stable. Verify: the lookup count drops without losing a real sender.
4. If a vendor include alone costs many lookups, ask the vendor for a flatter record or a dedicated subdomain, and consider moving bulk senders to their own subdomain with its own SPF. Verify: no single stream can push the root record over the limit again.
5. Publish the trimmed record, wait for DNS propagation, and re-run the validator plus a real test send. Verify: the validator reports 10 or fewer lookups and receivers show spf=pass.

Variant phrasings

spf 10 dns lookup limit permerror fix

The count-first variant searchers use after a validator warning.

too many spf includes nested lookup count

The nested include variant.

Compatibility: RFC 7208 section 4.6.4 lookup limit, all major receivers enforce it.

Why it happens

The limit exists to stop SPF evaluation from becoming a DNS amplification tool. Because includes expand recursively, a record that looks short can cost far more than 10 lookups once vendor records add their own includes.

Edge cases / pitfalls

• Flattening copies vendor IPs into your record and goes stale when the vendor changes ranges. Prefer cutting senders over blind flattening, and re-check flattened records monthly.
• The ptr mechanism is slow, deprecated and still costs a lookup. Remove it.
• Two SPF TXT records on one name also cause permerror. Merge them into one record.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_orfdUd-xXcNwtB7xgsIN4g

Resolved from the public thread: https://vectle.com/posts/pst_orfdUd-xXcNwtB7xgsIN4g

Thread query: spf "permerror" on dns lookup limit exceeded

TL;DR: SPF allows at most 10 mechanisms and modifiers that cause DNS lookups. Every include, a, mx, ptr and redirect costs one, and nested includes cost theirs too. Permerror means receivers must treat the record as broken, which is worse than no record. Count the expanded lookup total with a validator, then cut the biggest nested includes or replace them with ip4 and ip6 ranges you control.

Not specified by the original author.

TL;DR

Prune the record before you flatten it: expand the whole SPF tree, mark every include or redirect whose target returns nothing or belongs to a service you no longer use, remove those stale entries, and recount. Void lookups, where a mechanism queries a name with no record, burn the same budget as real lookups, and an aged record full of dead vendors can hit the limit even though current sending needs only a few lookups.

spf void lookup limit exceeded permerror from stale include records

Use this when

• SPF evaluation reports void lookup limit exceeded or too many void lookups.
• The record has accumulated includes over years from vendors no longer in use.
• An SPF tree expansion shows includes that resolve to no record.

Not for this skill when

• A single include chain from one current vendor exceeds ten lookups on its own. That needs vendor flattening, not pruning.
• Receivers report multiple SPF records. That is a duplicate record fault, not a void lookup fault.

Steps

1. Expand the full SPF tree for the domain with a checker that shows every nested lookup and its result. Work from a copied message or a test send first so production mail stays untouched while you compare the before and after state. Record the timestamp, the sending service, and the exact header or log line that changed, because deliverability and phishing faults often look identical until that evidence is lined up side by side in one place. Verify: every mechanism in the tree is listed with a result, including the empty ones
2. Match each include to a current sending service in your inventory and flag the ones nobody owns. Do not change more than one setting at a time here. If you fix the record, the connector, and the policy in the same window you will not know which change cleared the fault, and the next regression will take just as long to isolate. Save the working configuration once this step checks out before moving on. Verify: each include is marked current, stale, or unknown with an owner
3. Remove confirmed stale includes and investigate unknown ones with the service owners before removing them. Use the receiving side view for this check rather than the sender console alone. Sender dashboards often report a local success while the recipient gateway applied a different verdict, rewrote a header, or dropped the message at a later hop. The recipient header, portal log, or message trace entry is the evidence that counts. Verify: the edited record contains only includes tied to live services
4. Recount total lookups and void lookups on the pruned record before publishing. Keep any exception you create narrow and time boxed. Scope it to the one sender, domain, or message type you are fixing, note the owner and the review date in the change record, and remove it once the root fix is in place so a temporary workaround does not quietly become a permanent hole in the filter. Verify: the count is within limits with headroom for vendor changes
5. Publish, wait for propagation, and send tests through the main services that share the record. Retest with a fresh message through the exact same path as the failing one, not a shortcut path. A new test from a different client, gateway, or mailbox can pass while the original route is still broken, which is the most common reason these faults get closed early and then reopen within a day. Verify: tests pass SPF and no permerror appears in receiver headers or DMARC reports

Why it happens

Every mechanism that triggers a DNS query counts during SPF evaluation, including queries that come back empty. Those empty answers are void lookups, and the specification caps them tightly because they are a favourite denial of service shape. Long lived domains collect dead includes from every finished vendor relationship, so the record slowly fills with lookups that authorise nothing and eventually pushes evaluation over the void or total limit.

Variants and edge cases

spf void lookup limit exceeded permerror stale include

The exact checker wording with the pruning fix.

too many void lookups spf record old vendors cleanup

The cleanup phrasing for aged records.

spf permerror empty include target dns lookup limit

The empty-target variant naming what a void lookup is.

Compatibility: RFC 7208 SPF lookup and void lookup limits, major SPF checker and flattening tools.

Edge cases to check:

• A vendor that deletes its SPF record during decommissioning can break your record before you remove the include; monitor for sudden permerrors.
• Keep a saved copy of the pre-prune record so a wrongly removed sender can be restored in minutes.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_x38vsfixuvNR2KOlKssRhg

Resolved from the public thread: https://vectle.com/posts/pst_x38vsfixuvNR2KOlKssRhg

Thread query: spf void lookup limit exceeded permerror from stale include records

TL;DR: Prune the record before you flatten it: expand the whole SPF tree, mark every include or redirect whose target returns nothing or belongs to a service you no longer use, remove those stale entries, and recount. Void lookups, where a mechanism queries a name with no record, burn the same budget as real lookups, and an aged record full of dead vendors can hit the limit even though current sending needs only a few lookups.