Free SPF Record Validator

Validate your SPF record instantly. Check DNS lookup limits, inspect authorized senders, and catch syntax issues before they break email deliverability.

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Instant results

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What Is SPF?

SPF (Sender Policy Framework) is a DNS TXT record that defines which mail servers are authorized to send email on behalf of your domain. Receiving servers check this record to verify that incoming mail claiming to be from your domain is sent from an allowed source.

Why It Matters

Without SPF, anyone can send email using your domain. SPF is the first line of defense against spoofing and is required before DMARC can be effective.

Common Mistakes

Multiple SPF records, exceeding the 10 DNS lookup limit, and missing authorized third-party senders are the top causes of SPF failure and deliverability issues.

SENDER_IP

SPF_LOOKUP

MATCH_FOUND

PASS

SPF_ENGINE_V2

LOOKUPS: 4/10

How It Works

Input Domain

Type your root domain into the lookup tool above.

DNS Query

We query global DNS resolvers for your published SPF TXT record.

Analyze Record

Inspect mechanisms, includes, and total DNS lookup count.

Fix & Optimize

Remove unused includes, flatten chains, and stay under the limit.

Record Detection

Queries DNS resolvers globally to find your published SPF TXT record. Reports whether a record exists, how many are found, and flags multiple-record conflicts that break validation.

Lookup Counter

Counts every DNS lookup triggered by your SPF mechanisms and includes. Warns when you approach or exceed the RFC-mandated 10-lookup limit that causes permerror.

Include Chain

Traces nested include and redirect mechanisms to their final IP addresses. Helps you understand the full sender footprint and identify flattening candidates.

Syntax Check

Parses the full SPF record for illegal characters, unknown mechanisms, duplicate directives, and malformed syntax that can cause receiving servers to ignore the record.

Mechanism Audit

Reviews every mechanism (a, mx, ip4, ip6, include, exists, ptr) for correctness and coverage. Flags overly broad or missing entries that could allow spoofing.

Deliverability Score

Combines record presence, lookup count, syntax validity, and mechanism coverage into a quick health signal so you can assess overall SPF posture at a glance.

Frequently Asked Questions

What is an SPF record?

An SPF record is a DNS TXT record that lists the mail servers authorized to send email on behalf of your domain. Receiving servers use it to verify sender identity and reduce spoofing.

What is the SPF 10-lookup limit?

RFC 7208 limits SPF to 10 DNS lookups. Every include, a, mx, ptr, exists, and redirect counts. Exceeding 10 causes a permerror, which typically results in email rejection or spam routing.

Can I have multiple SPF records?

No. Multiple SPF records for the same domain cause ambiguity. Most receivers treat this as an error. Combine all authorized sources into a single SPF record.

What is the difference between ~all and -all?

~all (softfail) marks unauthenticated messages but still delivers them. -all (hardfail) tells receivers to reject unauthorized mail. Use -all only when all legitimate senders are listed in your SPF.

How do I reduce SPF lookups?

Remove unused include mechanisms, flatten nested includes to their final IP ranges, replace a and mx mechanisms with explicit ip4/ip6 ranges where possible, and use subdomains with separate SPF records for different services.

Is this SPF validator free?

Yes, this tool is 100% free with no signup required. For continuous SPF monitoring, lookup-limit alerting, and automated flattening recommendations, upgrade to CyberFurl Pro.

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