Home/Tools/AuthenticationAuthenticationSPF, DKIM, and DMARC inspectors and reporting tools for verifying sender authentication.Reading time: 3 minDifficulty: BeginnerEstimated duration: 3 minPrerequisites: NoneLast updated: July 2026Author: EmpireRelated learningDeliverabilityWhether mail is accepted and where it is placed — inbox, promotions, spam, or rejected.AuthenticationIdentity signals for email: SPF, DKIM, DMARC, and related controls.Related problemsGmail spam folderMail authenticated for your domain is accepted by Gmail but filed to Spam.Domain reputation degradedAuthenticated domain identity is treated as untrusted despite IP changes.Related toolsMXToolboxPopular DNS and mail diagnostics suite for SPF, DMARC, blacklist, and MX checks.Kitterman SPF validatorClassic web SPF policy evaluator used by operators for syntax checks.dmarcian inspectorsDMARC-focused inspectors and educational tooling from dmarcian.WorkflowsOpen step-by-step: Diagnose authentication failuresTrace SPF/DKIM/DMARC failures to a remediable cause.Open step-by-step: Audit multi-domain authenticationReview authentication across a domain portfolio.Open step-by-step: Authenticate a new domainPublish SPF, DKIM, and DMARC for a new sending domain and verify authentication before warmup.Open step-by-step: Recover from Gmail spamExit Gmail Spam using Postmaster signals, authentication fixes, and controlled volume.Open step-by-step: Check authenticationRegularly verify SPF, DKIM, and DMARC alignment and report pipelines.Continue LearningDeliverabilityTools that help diagnose and improve whether mail is accepted and trusted.PreviousToolboxNextDeliverability