SPF checker

SPF Checker

Look up a domain’s SPF TXT record and understand the mechanisms it uses to identify matching mail senders.

Free DNS lookup

Check a domain

Enter a domain, website URL, or email address. We’ll find and parse its published SPF record.

What SPF is

Sender Policy Framework (SPF) is a DNS policy used during email authentication to identify sending systems that can match for a domain.

When to use this checker

Use it to find a published SPF record, inspect its structure, or understand mechanisms, qualifiers, redirect information, and the final all policy.

What MailDNSLab checks

It requests TXT records, identifies the record beginning with v=spf1, and parses the supported mechanisms and qualifiers. It is not a full SPF evaluation engine.

Mechanisms and modifiers

include: Refers SPF evaluation to another domain’s published SPF policy.
a: Uses address records associated with a domain under SPF’s A/AAAA lookup behavior.
mx: Uses addresses of hosts identified through MX lookup behavior.
ip4 / ip6: Publishes an IPv4 or IPv6 address or network entry.
exists: Uses a DNS-existence test for its domain specification.
redirect=: Redirects policy evaluation to another domain when the modifier applies.
all: A catch-all mechanism that matches when evaluation reaches it.

Qualifiers and final policies

A mechanism without a written qualifier uses + by default. The final policy needs context: -all is not automatically correct, and ~all is not automatically insecure.

+ Pass: An explicit positive match; +all lets any sender match the catch-all.
- Fail: -all says senders not matched earlier should receive SPF Fail.
~ SoftFail: ~all gives unmatched senders a SoftFail result rather than Fail.
? Neutral: ?all makes no positive or negative assertion about unmatched senders.

What this checker does not evaluate

This view parses the published record. It does not:

Recursively resolve every include chain
Perform a complete RFC DNS-lookup-limit calculation
Test whether a specific sender IP is authorized
Visualize IP ranges or produce a deliverability score
Prove that mail will be accepted
Prove that SPF alone prevents spoofing

If multiple SPF records are found

Multiple v=spf1 records are a configuration problem. MailDNSLab reports each candidate and does not silently choose one. Review and consolidate the TXT configuration at the domain’s DNS provider.

Common questions

Does this checker follow every include or calculate the 10-DNS-lookup limit?

No. It displays parsed structure but does not recursively evaluate include chains or calculate the complete RFC lookup budget.

Why can a domain have many TXT records?

TXT is used by many services. MailDNSLab selects records identified as SPF and reports an error rather than choosing when more than one SPF record is present.

What should I do if SPF is missing or malformed?

Check the domain spelling, then review its DNS TXT configuration. A malformed result means an SPF-like record was found but could not be safely parsed.

Does SPF guarantee delivery?

No. SPF is one authentication signal. Delivery also depends on alignment, message handling, reputation, receiver policy, and other systems.

These tools answer different questions. Use either one when it fits your investigation; neither is a substitute for the current check.

DMARC CheckerReview the domain policy that uses SPF or DKIM alignment results.DKIM CheckerInspect the other authentication method that can participate in DMARC alignment.MX LookupCheck the separate DNS records used to route incoming mail.