Free SPF Record Checker & Syntax Validator
Inspect published Sender Policy Framework (SPF) records, validate recursive DNS query depth against the RFC 7208 10-lookup limit, and verify qualifier enforcement in seconds with zero waiting queues. SPF is the foundational email authentication standard that protects your brand name from malicious spoofing, phishing campaigns, and transactional delivery failures. When inbound mail servers at Google Workspace, Microsoft 365, and Yahoo Mail evaluate your emails, they verify whether the transmitting IP is declared inside your SPF TXT record. If your record is missing, misconfigured, or syntactically invalid, your customer notifications, invoices, and password reset links will land straight in spam folders.
Our free synthetic SPF validator performs an exhaustive recursive traversal of your DNS configuration. We count every nested mechanism, including include:, a, mx, exists, and redirect=, to ensure your configuration stays strictly under the 10 DNS query limit. In addition, Pingzo verifies qualifier enforcement rules (-all hardfail vs. ~all softfail), flags dangerous +all wildcards, and detects the fatal error of publishing multiple conflicting SPF records on a single host.
Unlike legacy lookup tools that show static text without actionable remediation guidance, Pingzo delivers high-resolution diagnostics with direct copy-paste solutions for Cloudflare, GoDaddy, Namecheap, and AWS Route 53. Simply enter your apex domain or sending subdomain below to audit your email deliverability posture in real time. Because marketing teams frequently integrate new third-party services that can silently push your record past the 10-lookup threshold, pair your manual checks with Pingzo's continuous 24/7 deliverability monitoring to receive instant multi-channel alerts via WhatsApp, Telegram, Slack, and Discord whenever your email records break.
Understanding SPF Record Structure & Common Pitfalls
Sender Policy Framework operates by publishing a plain-text TXT record on your DNS root. When a recipient mail server receives a message from your domain, it conducts a DNS query to find this record and evaluates the sender against your declared mechanisms:
Every include:, a, mx, or redirect= triggers an upstream DNS query. If the nested includes also contain more includes, the total lookup count compounds quickly. Once it exceeds 10, receiving mail servers abort evaluation with a permanent error (PermError).
The qualifier prefix dictates the enforcement policy. -all represents Hardfail (unauthorized servers are rejected outright), while ~all represents Softfail (unauthorized mail is marked as spam). Avoid using ?all (Neutral) or +all (Permits everyone).
Frequently Asked Questions
What is an SPF record and why is it mandatory for email delivery?
Sender Policy Framework (SPF) is a standard published in your domain DNS TXT records (starting with v=spf1). It lists the authorized IP addresses and third-party SaaS platforms (Google Workspace, Microsoft 365, SendGrid) allowed to send email from your domain. In 2024, Google and Yahoo made SPF authentication mandatory for inbox delivery.
What is the RFC 7208 10-DNS-lookup limit for SPF records?
To protect DNS resolvers from denial-of-service amplification attacks, RFC 7208 strictly limits the number of DNS-querying mechanisms (include, a, mx, ptr, exists, and redirect) to 10. If an SPF record triggers more than 10 lookups, receiving mail servers abort verification with an SPF PermError, frequently routing all your outbound emails directly to recipient spam folders.
What is the difference between -all (Hardfail) and ~all (Softfail)?
-all instructs receiving mailbox providers to immediately reject or quarantine any incoming email that fails SPF alignment. ~all (Softfail) marks unauthorized mail as suspicious but allows delivery. Security best practices recommend migrating to -all once all legitimate sending services are declared.
Why does Pingzo flag multiple SPF records as an invalid configuration?
RFC 7208 explicitly specifies that a domain name must publish at most one SPF TXT record. If a receiving server detects two or more SPF records (e.g. one for Google and one for SendGrid), it treats the result as a permanent error (PermError) and fails authentication for both.
How can I monitor my SPF records automatically so they never break?
Manual one-off lookups only reflect a single point in time. When marketing or sales teams connect new tools, they often add includes that silently push your record past 10 lookups. Pingzo automatically audits your SPF records daily and alerts your team via WhatsApp, Telegram, Slack, or Discord if your lookup count exceeds limits or records disappear.
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