SPF Validator

This tool validates SPF records for a given domain by retrieving DNS TXT records and compiling SPF policy fragments into a coherent policy. It identifies whether an SPF record exists, whether multiple records exist, and if the record contains valid syntax. It also flags common misconfigurations such as missing -all, redundant includes, or inappropriate redirect usage. Conceptually, the validator treats SPF as a policy that constrains which hosts may send mail on behalf of the domain and uses qualifiers to express permission or prohibition. The analysis is performed against RFC 7208 standards, focusing on mechanism types (ip4, ip6, include, mx, a, exists, redirect) and qualifiers (+, -, ~, ?) to determine a final stance on legitimacy and deliverability impact. The tool provides a concise policy summary and actionable remediation steps, making it valuable for operators managing large or client domains and for auditors verifying compliance with security policies. Its unique value lies in its automated parsing, cycle protection for includes, and clear guidance to fix common SPF mistakes that often cause mail to be rejected or placed in spam. Core features include DNS TXT retrieval, SPF record extraction, syntax validation, conflict detection, policy end-check (all vs redirect scenarios), and a structured remediation report. Use cases include pre-deployment SPF validation, post-change audits, and ongoing deliverability optimization for marketing and transactional domains.