Free SPF Record Lookup

Understanding SPF Records

SPF (Sender Policy Framework) is one of the three pillars of email authentication, alongside DKIM (DomainKeys Identified Mail) and DMARC (Domain-based Message Authentication, Reporting, and Conformance). Together, these protocols form a robust defense against email spoofing, phishing, and unauthorized use of your domain. SPF works by publishing a DNS TXT record that specifies which IP addresses and mail servers are permitted to send email on behalf of your domain.

When a receiving mail server gets a message, it extracts the domain from the envelope sender (Return-Path) and performs a DNS lookup for the SPF record. It then checks whether the sending server's IP address matches any of the authorized mechanisms listed in the record. The result — pass, fail, softfail, or neutral — influences whether the message is delivered, quarantined, or rejected. DMARC builds on this by aligning SPF and DKIM results with the visible "From" header domain, giving domain owners full control over how unauthenticated messages are handled.

Common mistakes with SPF include exceeding the 10 DNS lookup limit (which causes a permanent error), forgetting to add all third-party senders (like marketing platforms or CRM tools), using overly permissive mechanisms like +all, and not updating records when switching email providers. Use this tool to verify your SPF record is correct, then run a full DNS lookup to check all your domain's DNS records at once.