Email infrastructure tools

Email infrastructure tools

Correctness-led checks for publicly observable email infrastructure. Every finding explains what it found, why it matters, and how to fix it.

• Email domain health check

  A single public readiness view of a domain, composed from every individual check.

• SPF checker

  Validate an SPF record, count the 10-lookup and 2-void limits, and test whether an IP would pass.

• DMARC checker

  Read the DMARC policy, resolve the organisational domain, and check report authorisation.

• DKIM checker

  Read a DKIM key by selector, follow CNAME chains, and report the exact key size.

• DKIM selector finder

  Probe a list of common DKIM selectors for a domain.

• MX lookup

  List MX records, resolve each mail host, and identify the likely provider.

• MTA-STS checker

  Read the record and policy, and cross-validate the policy against the real MX records.

• TLS-RPT checker

  Check the TLS reporting record and its endpoints.

• BIMI checker

  Read the BIMI record, check DMARC eligibility, and safely inspect the logo.

• Reverse DNS checker

  Check the PTR record and forward-confirmed reverse DNS for an IP address.

• Domain age and registration lookup

  Registration date, age and registrar from RDAP, the registry's own data service.

• Non-sending domain checker

  Verify a domain that never sends mail is locked down: null MX, SPF -all and DMARC at reject.

• DANE/TLSA checker

  Check TLSA records and their DNSSEC state for every mail host, against the SMTP profile.

• SPF dependency tree

  Expand every include and redirect into a tree and see where the 10-lookup budget goes.

• Who sends email for a domain

  The publicly authorised sender picture: SPF tree, MX hosts and report receivers, with hedged identification.

• Tracking domain health check

  Check an ESP tracking domain: the CNAME chain, dangling-record risk and HTTPS.

• Bulk sender readiness check

  The DNS-observable half of the Gmail, Yahoo and Microsoft bulk sender rules, honestly separated from the half DNS cannot see.

• DMARC record builder

  Build a correct RFC 9989 record, checked against what the domain already publishes.

• URL redirect chain checker

  Follow a link you own hop by hop: statuses, http downgrades, loops and dead ends.

• BIMI SVG validator

  Validate a logo against the SVG Tiny PS profile: structure, scripting, references and size.

• Bounce code explainer

  Explain an SMTP bounce code or message, temporary or permanent, with next steps.

• List-Unsubscribe checker

  Check List-Unsubscribe and one-click headers. We never fetch the unsubscribe link.

• Authentication-Results explainer

  Explain SPF, DKIM, DMARC and ARC results from a pasted Authentication-Results header.

• DMARC aggregate report explainer

  Paste a RUA XML report and get it in plain English: volumes, pass rate, and which failing sources deserve attention.

• Email header analyzer

  Parse pasted email headers: the Received chain, authentication results and platform clues.