Header Analysis Tools

Paste raw headers to see a parsed breakdown of Received hops, timing, and Authentication-Results.

Parses raw headers and highlights SPF, DKIM, and DMARC results with delay calculations between hops.

Simple, fast header parser with a visual hop timeline.

Checks SPF syntax and counts DNS lookups against the 10-lookup limit.

Automated SPF flattening — converts include: mechanisms into static IP blocks and keeps them updated as ESP ranges change, keeping your record under the 10 DNS lookup limit.

Validates SPF records and flags common syntax errors.

Verifies a DKIM DNS record exists and is properly formatted for a given domain and selector.

Checks DKIM alongside MX, SPF, and DMARC in one combined report.

Send a test email to check@verifier.port25.com and it sends back a full authentication report by email.

Full DMARC aggregate report processing, SPF flattening automation, and infrastructure change alerts.

Validates DMARC record syntax and policy tags.

DMARC aggregate report dashboard with authentication governance features. Free tier available.

Send a test email and get a full 0-10 deliverability score covering SPF, DKIM, DMARC, content, and blocklist status.

Inbox placement testing across major mailbox providers.

Gmail-specific delivery reputation, spam rate, and authentication insights for verified domains.

Checks a sending IP against dozens of major DNSBLs simultaneously.

Visualizes full DNSSEC chain validation, useful when troubleshooting DANE deployments.

Domain and IP ownership lookup for forensic investigation.