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Quick checks

Internet Speed TestConnection QualityGeographic LocationIPv4 / IPv6 Readiness

Insights & reports

Guided TroubleshootingConnection ComparisonReliability MonitorNetwork Health SummarySupport ReportService HealthWebsite & Path TesterNetwork Change ComparisonShareable Status Report

Technical tools

Ping TestPort TestNetwork AnalyzerMAC Vendor FinderSSL Certificate CheckerRDAP Domain & IP LookupWireless Password GeneratorEvidence Report Verifier

Email & DNS

Toolkit overviewSPF evaluatorDKIM validatorHeader analyserDMARC report readerEmail domain healthDNSSEC & DANEConfiguration preflightDiagnostic case workspaceDNS, TLS & policy monitorGenerators & bulk DNSDNS lookupAuthoritative DNS trace

Plan a network

Subnet CalculatorFibre Cable GuideSwitch/Firewall Cheat SheetFirewall Migration Planner

Help & Privacy

Tool GuidesHelp, accuracy & privacySaved Data & PrivacyRights & LicensingRelease NotesAdministrator sign-in
Read the Email Header Analyser guide
!Email and DNS toolkit limitationsResults are public-DNS observations, local parsers and bounded cryptographic checks—not proof of identity, delivery, reputation or compliance.Expand disclaimerCollapse disclaimer⌄

Message and DMARC inputs remain in the browser, but copying, forwarding or exporting can alter evidence. DKIM RSA-SHA256 verification depends on complete unmodified source and the currently published key; unsupported algorithms are labelled. DNSSEC uses public-resolver validation plus DS digest matching, while some TLSA selectors cannot be byte-matched in this runtime. No SMTP server is required or contacted. Monitoring stops when its page closes. Live delivery, mailbox acceptance, commercial reputation, inbox-placement and proprietary blacklist coverage are excluded.

Important: Do not rely on this result alone for purchasing, configuration, security, safety, compliance, contractual or fault-diagnosis decisions. Results can be incomplete, delayed, misleading or wrong. Verify important findings with the relevant provider, manufacturer documentation and an appropriate independent test or qualified professional.

Delivered-message evidence

Email and .eml analyser

Open a complete .eml file or paste headers to inspect the route, timing, authentication, identities and attachment names entirely in this tab.

OverviewSPF EvaluatorDKIM ValidatorEmail Header AnalyserDMARC Report ReaderEmail Domain HealthDNSSEC & DANEEmail DNS Configuration PreflightDiagnostic Case WorkspaceEmail Policy MonitorEmail Record Generators & Bulk DNS

Browser-only input: message content is never uploaded, saved, put into analytics or browser storage. It is cleared when you leave or press Clear. Maximum input: 2 MB. DNS names needed for public-key lookup are sent to the site resolver.

Warning: headers can be forged before a trusted receiving hop. Treat Authentication-Results as trustworthy only when added by a system you trust, and compare with the original message source.

Abuse protection

Confirm you are human

Complete this free security check before using bandwidth-heavy or technical diagnostic tools. It helps keep the service available without storing your public IP address in shared results.

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A successful check remains valid in this browser for up to 30 minutes. Cloudflare Turnstile processes the verification.

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Production release 2026.09.19

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