# dns.rehab

> dns.rehab is a free DNS and email-deliverability diagnostics service by Marketstead: enter a domain, get a graded audit (nameservers, SPF, DKIM, DMARC, BIMI, MTA-STS, TLSRPT, DNSBL blacklists, LLM policy) with every verdict explained in plain English and every problem paired with a fix.

Run the audit at https://dns.rehab/ — no account, one input field, results in under a minute at a stable permalink you can share.

## Tools

- [The dns: deep audit](https://dns.rehab/tools/dns-audit): intodns-class walk — delegation vs authoritative NS, SOA serials and timers per RFC 1912, open-recursion probing, glue validation, provider-aware heuristics.
- [SPF checker](https://dns.rehab/tools/spf): RFC 7208-exact walk with the 10-lookup budget counted as it is spent.
- [DKIM checker](https://dns.rehab/tools/dkim): selector probing with key-size and revocation checks.
- [DMARC checker](https://dns.rehab/tools/dmarc): policy and reporting tags with the none → quarantine → reject ladder.
- [BIMI checker](https://dns.rehab/tools/bimi): record validation with the honest VMC/SVMC requirements.
- [MTA-STS checker](https://dns.rehab/tools/mta-sts): TXT + /.well-known/ policy file, both halves graded.
- [TLSRPT checker](https://dns.rehab/tools/tlsrpt): failure-report address validation.
- [Blacklist check](https://dns.rehab/tools/blacklist): curated ~24-zone DNSBL verdicts with per-zone delisting links.
- [llms.txt checker](https://dns.rehab/tools/llms-txt): files graded against the llmstxt.org v2 spec.
- [AI crawler policy check](https://dns.rehab/tools/robots-llm): named AI crawler rules in robots.txt, silent-policy detection.
- [Email header analyzer](https://dns.rehab/tools/header-analyzer): Received chain hop-by-hop plus SPF/DKIM/DMARC verdict explanations.

## Reports

- [Example audit report](https://dns.rehab/): run any domain at the home page to get a permalinked, shareable graded report.

## Optional

- [About Marketstead](https://marketstead.com): the operator behind dns.rehab — managed DNS, email hosting and deliverability services.