--- title: "SPF Too Many DNS Lookups - How to Fix It | AutoSPF" description: "Exceeding the SPF 10-DNS-lookup limit causes a permanent error (permerror) that breaks email authentication. Learn why it happens and how SPF flattening fixes it." image: "https://autospf.com/images/og-default.png" canonical: "https://autospf.com/spf-too-many-dns-lookups/" --- Common SPF Problem # SPF Too Many DNS Lookups The SPF 10-lookup limit is the most common cause of email authentication failures. Here's what it is, why it happens, and how to fix it. Exceeding 10 lookups causes SPF permerror ## Check Your SPF Lookup Count Now Enter your domain to see exactly how many DNS lookups your SPF record uses - and whether you're over the limit. Enter your domain name Check SPF Record Type a domain to see its published SPF record, a mechanism-by-mechanism breakdown, and a live DNS lookup count. Understanding SPF ## What is an SPF Lookup? An SPF lookup is the process where an email server queries the DNS record of the sender's domain to confirm whether a particular IP address is authorized to send emails on behalf of that domain. RFC 7208 imposes a maximum of **10 DNS lookups** per SPF evaluation. Each `include`, `a`, `mx`, `ptr`, and `redirect` mechanism counts toward this limit. Exceeding it causes an SPF permanent error (permerror), making your entire SPF record invalid. The Challenge ## Why the 10-Lookup Limit is a Challenge 1 ### Multiple Third-Party Services Each vendor (Google Workspace, Mailchimp, Salesforce, HubSpot) adds at least one include to your SPF record. Modern businesses often use 5+ email-sending services. 2 ### Nested SPF Records An include mechanism often references other domains with their own includes, creating a chain of lookups that quickly exceeds the limit. 3 ### Complex SPF Setups Using the ptr mechanism, complex modifiers, and expansive IP lists all contribute to more DNS lookups than necessary. 4 ### Wrong Configuration Broken mechanisms and improper configurations cause failed SPF checks, prompting servers to perform additional lookups in an attempt to validate the message. ## What Happens When You Exceed the Limit? - x Your SPF record returns a **permerror** (permanent error), making it completely invalid - x Receiving servers may **reject your legitimate emails** or route them to spam - x DMARC alignment breaks because SPF authentication fails - x Your domain's sender reputation degrades over time The Solution ## How SPF Flattening Fixes the Problem SPF flattening (also called SPF compression) resolves the lookup limit by replacing all `include` statements and domain references with their underlying IP addresses. The consolidated record is then published in your domain's DNS, eliminating the need for recursive lookups. AutoSPF automates this process by continuously monitoring your SPF includes every \~15 minutes. When any underlying IP addresses change, the flattened record is automatically updated - no manual intervention required. ### Benefits of SPF Flattening - Eliminates the DNS lookup limit error - Ensures unaffected email delivery - Supports proper DKIM and DMARC operations - Improves sender reputation - Protects against phishing and spoofing attacks ### SPF Lookup Counter Use an SPF lookup counter tool to see how many DNS lookups your current SPF record requires. If you're at or near 10, it's time to flatten. [Check your SPF record →](/tools/spf-checker/) ## Fix SPF Too Many DNS Lookups - Automatically AutoSPF flattens your SPF record and keeps it updated in real time. Setup takes 60 seconds. [Start Free Trial→](https://subscriptions.zoho.com/subscribe/31162770c20bc42aba9c86185ed6106a6a2bba0f6b053217ad482bf477cf719e/smb%5F1)[View Plans & Pricing](/pricing/) Rated 5/5 on G2 · Trusted since 2018 ## What Our Customers Say ### "AutoSPF Flattens SPF Records Seamlessly & Keeps Changes Logged - I am quite pleased with the product" > It does what it promises to do, and does it very well. I appreciate that it keeps a log of changes made, which prevents many mistakes. A client's SPF record would have way too many lookups, but AutoSPF makes that problem go away. The length of the SPF record is typically not the issue; it's the amount of lookups in the record that are. AutoSPF "flattens" the record, automatically expanding the defined lookups to IP addresses or ranges. And it auto-updates the record when the un-flattened lookups change. PJ Peter J. President · Small-Business (50 or fewer emp.) ### "Helped us go beyond capacity" > AutoSPF did exactly as described, it helped us get past our 10 lookup limit. Afterwards, we hit another limit regarding overall capacity and when contacted, they quickly provided us with a new solution to eliminate capacity issues entirely going forward, so now we can add as many SPF records as needed. They also provided us with a personalized support video explaining their new method in its entirety using our instance as the example. VU Verified User Financial Services · Mid-Market (51-1000 emp.) [Read our reviews on G2 ](https://www.g2.com/products/autospf/reviews) ```json {"@context":"https://schema.org","@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897474","name":"AutoSPF","url":"https://autospf.com","logo":{"@type":"ImageObject","url":"https://autospf.com/images/autospf-logo.png"},"description":"Automatic SPF flattening and email authentication management. 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Resolve SPF lookup limits, flatten SPF records, and maintain email deliverability across all your domains.","publisher":{"@type":"Organization","name":"AutoSPF","url":"https://autospf.com","logo":{"@type":"ImageObject","url":"https://autospf.com/images/autospf-logo.png"},"description":"Automatic SPF flattening and email authentication management. Resolve SPF lookup limits, flatten SPF records, and maintain email deliverability across all your domains.","parentOrganization":{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138883901","name":"DuoCircle LLC","url":"https://www.duocircle.com","sameAs":["https://www.wikidata.org/wiki/Q138883901","https://www.crunchbase.com/organization/duocircle-llc","https://www.linkedin.com/company/duocircle","https://github.com/duocircle"],"subOrganization":[{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138898167","name":"DMARC Report","url":"https://dmarcreport.com"},{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897474","name":"AutoSPF","url":"https://autospf.com"},{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897912","name":"Phish Protection","url":"https://www.phishprotection.com"}]}}} ``` ```json {"@context":"https://schema.org","@type":"FAQPage","mainEntity":[{"@type":"Question","name":"What does \"SPF Too Many DNS Lookups\" mean?","acceptedAnswer":{"@type":"Answer","text":"It means your SPF record requires more than 10 DNS mechanism lookups (include, a, mx, redirect, exists) during evaluation. RFC 7208 §4.6.4 caps evaluation at 10 lookups - exceeding this produces a PermError that fails SPF authentication for every message from the domain, regardless of whether the sender is authorized."}},{"@type":"Question","name":"How many DNS lookups does my SPF record use?","acceptedAnswer":{"@type":"Answer","text":"Use a free SPF checker tool to count automatically. Each include, a, mx, redirect, and exists mechanism consumes 1 lookup, plus any nested lookups inside included records. The ip4 and ip6 mechanisms consume 0 lookups because they are literal IP addresses with no DNS resolution needed."}},{"@type":"Question","name":"How do I fix the 10-lookup limit?","acceptedAnswer":{"@type":"Answer","text":"The two main fixes are SPF flattening (replacing include mechanisms with resolved IP addresses, which consume 0 lookups) and SPF macros (delegating per-query resolution so lookups happen on the vendor side, not your record). AutoSPF automates both approaches and re-scans upstream vendor IP changes every 15 minutes."}},{"@type":"Question","name":"Does the 10-lookup limit count nested includes?","acceptedAnswer":{"@type":"Answer","text":"Yes. If your record includes vendor A, and vendor A's SPF record includes vendor B, that chain consumes 2 lookups from your budget of 10 - not 1. Google Workspace alone uses 4 lookups (1 top-level + 3 netblocks), and SendGrid uses approximately 5."}},{"@type":"Question","name":"What is the difference between SPF flattening and SPF macros?","acceptedAnswer":{"@type":"Answer","text":"SPF flattening replaces include mechanisms with their resolved IP addresses, reducing lookup count to near zero but requiring periodic updates when vendor IPs change. SPF macros use RFC 7208 macro syntax to delegate lookups to a dynamic resolver at query time, bypassing the 10-lookup limit entirely. Macros are more flexible but require a managed service to operate."}},{"@type":"Question","name":"Will exceeding 10 lookups affect my email deliverability?","acceptedAnswer":{"@type":"Answer","text":"Yes - exceeding the limit causes a PermError, which means every email from your domain fails SPF authentication. Gmail, Outlook.com, and Yahoo enforce SPF strictly, so failed authentication leads to messages being rejected or routed to spam. DMARC alignment also breaks because SPF cannot pass."}}]} ``` ```json {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://autospf.com/"},{"@type":"ListItem","position":2,"name":"SPF Too Many DNS Lookups","item":"https://autospf.com/spf-too-many-dns-lookups/"}]} ``` ```json {"@context":"https://schema.org","@type":"Product","name":"AutoSPF","url":"https://autospf.com","aggregateRating":{"@type":"AggregateRating","ratingValue":5,"reviewCount":21,"bestRating":5,"worstRating":1},"review":[{"@type":"Review","reviewRating":{"@type":"Rating","ratingValue":5,"bestRating":5},"author":{"@type":"Person","name":"Peter J.","jobTitle":"President"},"datePublished":"2026-03-10","reviewBody":"It does what it promises to do, and does it very well. I appreciate that it keeps a log of changes made, which prevents many mistakes. A client's SPF record would have way too many lookups, but AutoSPF makes that problem go away. The length of the SPF record is typically not the issue; it's the amount of lookups in the record that are. AutoSPF \"flattens\" the record, automatically expanding the defined lookups to IP addresses or ranges. And it auto-updates the record when the un-flattened lookups change.","name":"AutoSPF Flattens SPF Records Seamlessly & Keeps Changes Logged - I am quite pleased with the product","publisher":{"@type":"Organization","name":"G2","url":"https://www.g2.com"}},{"@type":"Review","reviewRating":{"@type":"Rating","ratingValue":5,"bestRating":5},"author":{"@type":"Person","name":"Verified User","jobTitle":"Financial Services"},"datePublished":"2025-07-31","reviewBody":"AutoSPF did exactly as described, it helped us get past our 10 lookup limit. Afterwards, we hit another limit regarding overall capacity and when contacted, they quickly provided us with a new solution to eliminate capacity issues entirely going forward, so now we can add as many SPF records as needed. They also provided us with a personalized support video explaining their new method in its entirety using our instance as the example.","name":"Helped us go beyond capacity","publisher":{"@type":"Organization","name":"G2","url":"https://www.g2.com"}}]} ```