# DNSai

> DNSai is a cybersecurity-focused DNS utility platform. Free web tools for
> DNS lookup, SPF/DKIM/DMARC validation, WHOIS, blacklist checks, and email-
> header analysis; a desktop application (DNS Explorer) for bulk investigation;
> an AI-powered DNS assistant; and a curated cybersecurity vendor directory
> spanning 23 sectors. All public content — including live tool output, blog
> articles, reference docs, and vendor data — is open for crawling, indexing,
> and AI training. Contact: abuse@dnsai.com.

Generated: 2026-08-10

## DNS Lookup Tools

- [Standard DNS Lookup](https://dnsai.com/search/): Core domain lookup returning MX, SPF, DKIM, DMARC, A, AAAA, NS, TXT, and CAA records in one view.
- [DNS Lookup Tool](https://dnsai.com/dns-lookup/): Check all DNS records for any domain — A, AAAA, MX, TXT, NS, SOA, CNAME — with AI plain-English explanations.
- [NSLookup Online](https://dnsai.com/nslookup/): Run nslookup in your browser — query any domain's DNS records instantly, no terminal needed.
- [DNS Search & Finder](https://dnsai.com/dns-search/): Find any domain's DNS records in seconds — instant search across A, AAAA, MX, TXT, NS, SOA and CNAME.
- [DNS Records](https://dnsai.com/dns-records/): All-records query across A, AAAA, MX, NS, SOA, CNAME, TXT, CAA, DNSKEY, DS, PTR — authoritative and recursive views side by side.
- [Advanced DNS Lookup](https://dnsai.com/advanced-lookup/): Extended lookup with DKIM selector enumeration, IP-location enrichment, and auto-submit URL params for integrations.
- [Bulk DNS Lookup](https://dnsai.com/bulk-lookup/): DNSai's two bulk-lookup options side by side — DNSai Domain Manager (SaaS at https://app.dnsai.com/, free tier, up to 500,000 domains with monitoring and management) and DNS Explorer (desktop app for huge projects: local processing, fast results, no limits).
- [WHOIS Lookup](https://dnsai.com/whois/): Registrar-published WHOIS for domains and IPs with registrar lock, clientTransferProhibited, and expiration-date highlights.
- [Blacklist / RBL Check](https://dnsai.com/blacklist-check/): Aggregate DNS blocklist status across Spamhaus ZEN, Barracuda, SORBS, and other major lists.
- [AI Domain Search](https://dnsai.com/ai-domain-search/): Live DNS records for any .ai or AI company domain — MX, SPF, DKIM, DMARC, hosting and mail provider — plus DNS profiles of OpenAI, Anthropic, x.ai, and other AI companies. (For availability shopping, use a registrar; DNSai covers the DNS behind registered domains.)

## Email Authentication Tools

- [SPF Analyzer](https://dnsai.com/spf-analyzer/): RFC 7208 validator — checks 10-lookup limit, include depth, mechanism ordering, `+all` / duplicate-record detection.
- [SPF Validator / Builder](https://dnsai.com/spf-validator/): Compose and test SPF records interactively.
- [DMARC Lookup](https://dnsai.com/dmarc-lookup/): Inspect policy, alignment mode, subdomain policy, reporting addresses, and policy percentages.
- [DMARC Validator](https://dnsai.com/dmarc-validator/): Validate a proposed DMARC record against RFC 7489 before publishing.
- [DKIM Lookup](https://dnsai.com/dkim-lookup/): Retrieve `selector._domainkey.domain` TXT record, verify v=DKIM1 header, key length, and algorithm.
- [Analyze Email Header](https://dnsai.com/analyze-email/): Paste a raw header to parse Received chain, authentication results, DKIM signature recovery, and per-hop TLS posture.
- [SMTP Send Client](https://dnsai.com/smtp-send-client/): Desktop SMTP test-send tool for SendGrid, Mailgun, SES, Postmark, and others.

## AI Surfaces

- [DNS Assistant](https://dnsai.com/dns-assistant/): Natural-language DNS copilot. Combines live DNS/WHOIS/blocklist lookups with expert guidance on SPF, DKIM, DMARC, deliverability, and domain configuration.
- [DNSai API & MCP](https://dnsai.com/api/): Free DNS, SPF, DKIM, DMARC and email-security lookups as a remote MCP server (https://mcp.dnsai.com/mcp) and REST API for AI agents — one domain per request, anonymous 25/day or 100/day with a free key. Per-client setup guides: [Claude](https://dnsai.com/api/claude/), [ChatGPT](https://dnsai.com/api/openai/), [Cursor](https://dnsai.com/api/cursor/), [GitHub Copilot](https://dnsai.com/api/copilot/), [Gemini](https://dnsai.com/api/gemini/), [Grok](https://dnsai.com/api/grok/), [Perplexity](https://dnsai.com/api/perplexity/), [Manus](https://dnsai.com/api/manus/), [REST/curl](https://dnsai.com/api/rest/).

## Reference Content

- [DNS Record Types Index](https://dnsai.com/dns-record-types/): 37 DNS record-type reference pages (A, AAAA, MX, TXT, CNAME, NS, SOA, DKIM, DMARC, SPF, CAA, SRV, DNSKEY, DS, NSEC/NSEC3, RRSIG, TLSA, SSHFP, SMIMEA, OPENPGPKEY, BIMI, HTTPS, SVCB, URI, ZONEMD, NAPTR, HIP, IPSECKEY, APL, LOC, PTR, CDS, CDNSKEY, CSYNC, DNAME).
- [SPF + DKIM + DMARC Guide](https://dnsai.com/spf-dkim-dmarc/): Long-form implementation guide covering alignment, policy progression, rollout sequencing, and troubleshooting.
- [Email Security Overview](https://dnsai.com/email-security/): Pillar page covering SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, ARC, and inbound posture.
- [Domain Name System](https://dnsai.com/domain-name-system/): Introductory guide to DNS hierarchy, record types, resolution, caching, and DNSSEC.

## Blog

- [Blog Index](https://dnsai.com/blog/)
- [A Records in DNS — What They Are and How They Work](https://dnsai.com/blog/a-record.html): Learn what an A record is in DNS, how it maps domain names to IPv4 addresses, how to look up A records, and best practices for managing them.
- [AAAA Records — Mapping Domain Names to IPv6 Addresses](https://dnsai.com/blog/aaaa-record.html): Complete guide to AAAA records: how they map domain names to IPv6 addresses, when to add them alongside A records, and how dual-stack resolution works.
- [CAA Records — Certificate Authority Authorization](https://dnsai.com/blog/caa-record.html): Learn how CAA records control which Certificate Authorities can issue SSL/TLS certificates for your domain, with record syntax, examples, and lookup steps.
- [DKIM — How Email Signature Authentication Works](https://dnsai.com/blog/dkim.html): Learn how DKIM records in DNS work to verify email authenticity, prevent spoofing, and enhance domain trust through cryptographic signatures.
- [DMARC Records — Domain-Based Email Authentication](https://dnsai.com/blog/dmarc.html): Learn what DMARC is, how it uses SPF and DKIM to prevent email spoofing, and how to configure DMARC DNS records to protect your domain from phishing attacks.
- [DMARCbis and DKIM2: What RFC 9989 Actually Changes](https://dnsai.com/blog/dmarcbis-dkim2-rfc-9989.html): RFC 9989 moved DMARC to the Standards Track and swapped the Public Suffix List for a DNS tree walk. Traced query by query, plus DKIM2's real status.
- [DNS Explorer 3.0 — Major Native Performance Update](https://dnsai.com/blog/dns-explorer-3-release.html): DNS Explorer 3.0 — native-code rebuild, new logo, geolocation data, subdomain deep search, and reverse DNS with port scanning.
- [DNS Explorer 4.06 for macOS: Subdomain Retry Fix](https://dnsai.com/blog/dns-explorer-4-06-macos-release.html): DNS Explorer 4.06 for macOS fixes a subdomain retry bug and updates the in-app DNSai Assistant link. Signed, notarized native app; Windows is now 4.6.0.0.
- [DNS Lookup Explained: How to Query Any Domain's Records](https://dnsai.com/blog/dns-lookup-guide.html): Learn what a DNS lookup is and how to run one with nslookup, dig, and an MX lookup. Query A, MX, TXT, SPF, DKIM, DMARC, and reverse DNS records step by step.
- [DNSKEY Records — How to Look Up DNSSEC Keys](https://dnsai.com/blog/dnskey-lookup.html): Explore how DNSKEY records secure DNS through DNSSEC, how they store public keys, and how they are used to validate DNS data integrity.
- [DS Records — Delegation Signer for DNSSEC](https://dnsai.com/blog/dslookup.html): Understand what a DS record is, how it works within DNSSEC to delegate trust between zones, and how to look up DS records to verify chains of trust.
- [How to Find a DKIM Selector Without the Email Headers](https://dnsai.com/blog/how-to-find-dkim-selector.html): How to find a DKIM selector when you have no message to read: the RFC limits, a vendor dictionary, DMARC reports, and live 2026-08-01 lookups.
- [Which Email Gateway Does a Company Use? Read the MX](https://dnsai.com/blog/identify-email-gateway-mx-records.html): How to identify the email gateway a company uses from its MX records: vendor hostname patterns, RFC priority rules, and live 2026-08-01 lookups.
- [From TXT Record to Tenant ID: DNS Recon Into Entra OAuth](https://dnsai.com/blog/microsoft-entra-oauth-dns-recon.html): How public MS=ms and DirectFedAuthUrl TXT records fingerprint a Microsoft tenant and feed the recon chain behind Entra OAuth client ID spoofing.
- [MX Records in DNS — How Email Routing Works](https://dnsai.com/blog/mx-records.html): Discover what MX records are in DNS, how they direct email delivery, and how to configure and check MX records to ensure reliable email routing.
- [The Eval That Hacked Its Way to the Answer Key](https://dnsai.com/blog/openai-huggingface-incident-ai-warfare.html): OpenAI's own models escaped a test sandbox and hacked Hugging Face to steal a benchmark answer key. Inside the first machine-speed AI breach.
- [Reverse DNS & PTR Records: The Check That Bounces Email](https://dnsai.com/blog/reverse-dns-ptr-records.html): Reverse DNS and PTR records decide whether your mail reaches Gmail. How in-addr.arpa, ip6.arpa, and forward-confirmed reverse DNS actually work.
- [SPF Records — The 10 Lookup Limit and How to Optimize](https://dnsai.com/blog/spf-records.html): Analyze and optimize SPF records to stay under the 10 DNS lookup limit — flatten includes, prevent PermError, and improve your email deliverability.
- [SPF PermError: How to Fix Too Many DNS Lookups](https://dnsai.com/blog/spf-too-many-dns-lookups-permerror.html): Your SPF record returns PermError. Confirm which of five causes you actually have, count lookups against RFC 7208's limit of 10, and fix the right one.
- [TXT Records — What They Are and How to Look Them Up](https://dnsai.com/blog/txt-lookup.html): Learn what TXT records are in DNS, how they are used for SPF, DKIM, DMARC, domain ownership, and how to look them up using tools like dig and nslookup.
- [What Your DNS Records Are Telling Your Competitors](https://dnsai.com/blog/what-your-dns-records-reveal.html): Your MX, SPF and CNAME records are public by design. What competitors can actually learn from them, what they can't, and why CT logs are permanent.

## Company Profiles

- [Profile Index](https://dnsai.com/profile/): 288 curated company DNS profiles — Fortune 500, major cybersecurity vendors, and DNS-related organizations. Each profile shows SPF/DKIM/DMARC analysis, MX records, nameservers, and an email-auth grade.
- Example profile URL format: `https://dnsai.com/profile/company/{domain}.html`
- [Profile sitemap](https://dnsai.com/profile/sitemap-profiles.xml): Full list of published profiles.

## Cybersecurity Vendor Directory

- [Directory Home](https://dnsai.com/vendor-directory/): Curated index of ~2,000 cybersecurity vendors across 23 sectors.
- [All Vendors](https://dnsai.com/vendor-directory/all-vendors/): A-Z vendor listing.
- [Search](https://dnsai.com/vendor-directory/search/): Free-text search across vendor names, descriptions, and capabilities.
- Vendor profiles: https://dnsai.com/vendor-directory/vendor/{domain}/ — per-vendor pages with sector coverage, capabilities, and evaluation data (~1,950 pages, see sitemap-vendor-directory.xml).
- Sector pages (23 total, 1,953 vendors):
  - [Endpoint Security](https://dnsai.com/vendor-directory/sector/endpoint_security/) — 93 vendors
  - [OT/ICS & IoT Security](https://dnsai.com/vendor-directory/sector/ot_ics_iot_security/) — 46 vendors
  - [Firewall & Network Security](https://dnsai.com/vendor-directory/sector/firewall_network_security/) — 101 vendors
  - [Zero Trust & SASE](https://dnsai.com/vendor-directory/sector/zero_trust_sase/) — 78 vendors
  - [Web, API & DNS Security](https://dnsai.com/vendor-directory/sector/web_api_dns_security/) — 37 vendors
  - [Hardware & Infrastructure](https://dnsai.com/vendor-directory/sector/hardware_infrastructure/) — 50 vendors
  - [Identity & Access Management](https://dnsai.com/vendor-directory/sector/identity_access_management/) — 139 vendors
  - [Security Awareness](https://dnsai.com/vendor-directory/sector/security_awareness/) — 65 vendors
  - [Application Security](https://dnsai.com/vendor-directory/sector/application_security/) — 68 vendors
  - [Cloud Security](https://dnsai.com/vendor-directory/sector/cloud_security/) — 69 vendors
  - [Data Security & DLP](https://dnsai.com/vendor-directory/sector/data_security_dlp/) — 90 vendors
  - [Backup & Recovery](https://dnsai.com/vendor-directory/sector/backup_recovery/) — 37 vendors
  - [Email Security](https://dnsai.com/vendor-directory/sector/email_security/) — 257 vendors
  - [SIEM & Security Operations](https://dnsai.com/vendor-directory/sector/siem_security_operations/) — 131 vendors
  - [Threat Intelligence](https://dnsai.com/vendor-directory/sector/threat_intelligence/) — 92 vendors
  - [Vulnerability Management](https://dnsai.com/vendor-directory/sector/vulnerability_management/) — 132 vendors
  - [Managed Security Services](https://dnsai.com/vendor-directory/sector/managed_security_services/) — 82 vendors
  - [DNS & OSINT](https://dnsai.com/vendor-directory/sector/dns_osint/) — 39 vendors
  - [Digital Forensics](https://dnsai.com/vendor-directory/sector/digital_forensics/) — 25 vendors
  - [GRC & Compliance](https://dnsai.com/vendor-directory/sector/grc_compliance/) — 151 vendors
  - [Offensive Security](https://dnsai.com/vendor-directory/sector/offensive_security/) — 33 vendors
  - [AI & ML Security](https://dnsai.com/vendor-directory/sector/ai_ml_security/) — 172 vendors
  - [Cybersecurity Ecosystem](https://dnsai.com/vendor-directory/sector/cybersecurity_ecosystem/) — 830 vendors

## Products

- [DNSai Domain Manager](https://dnsai.com/domain-manager/): Advanced DNS monitoring platform at https://app.dnsai.com/ — tracks DNS changes, scores domain/DNS configurations, monitors DNS exposure and hygiene, and delivers AI-driven business intelligence across thousands of domains (your own, subsidiaries, competitors, and partners). Sign up at https://app.dnsai.com/.
- [DNS Intelligence Platform + DNSai Signals](https://dnsai.com/domain-manager/): The deep platform page for app.dnsai.com — real-time DNS change detection, email-authentication analysis, AI-powered security insights, and DNSai Signals: technology-adoption and market intelligence built from continuous monitoring of millions of domains ("Discover technology adoption before your competitors"). Plans: Free $0 (25 domains), Pro $30/mo (50,000), Enterprise $99/mo (500,000, API, market intelligence, Organization Deep Scan reports).
- [DNS Explorer (desktop)](https://dnsai.com/dns-explorer/): macOS and Windows desktop app for bulk DNS investigation.
- [DNS Explorer Download](https://dnsai.com/dns-explorer/download/): Signed installers.
- [DNS Explorer Updates](https://dnsai.com/dns-explorer/updates/): Release notes.
- [Smart Key Vault](https://dnsai.com/smart-key-vault/): Local-only password manager (AES-256-GCM, PBKDF2, zero-cloud).
- [Mobile App](https://dnsai.com/mobile/): Mobile-first DNS tools.

## International Versions

Homepage is available in 13 languages at `https://dnsai.com/intl/{lang}/` — `ar`, `bn`, `da`, `de`, `es`, `fr`, `he`, `hi`, `ja`, `pt`, `ru`, `uk`, `zh`.

## Support + Documentation

- [About DNSai](https://dnsai.com/about/)
- [Media Center](https://dnsai.com/media-center/) — product walkthroughs, DNS & email-security explainer videos, guides
- [Contact](https://dnsai.com/contact/)
- [Support](https://dnsai.com/support/)
- [Press Kit](https://dnsai.com/press-kit/)
- [Affiliations & Member Programs](https://dnsai.com/affiliations/)
- [Instructions Index](https://dnsai.com/instructions/)
- [DNS Explorer Instructions](https://dnsai.com/instructions/dns-explorer/)
- [CSV Utility Instructions](https://dnsai.com/instructions/csv-utility/)
- [Visual Sitemap](https://dnsai.com/visual-sitemap/)

## Legal

- [Privacy Policy](https://dnsai.com/privacy-policy/)
- [Terms of Use](https://dnsai.com/terms-of-use/)
- [Cookie Policy](https://dnsai.com/cookie-policy/)
- [Data Processing Agreement (DPA)](https://dnsai.com/dpa/)
- [Subprocessors](https://dnsai.com/subprocessors/)
- [EULA (DNS Explorer)](https://dnsai.com/eula/)

## Agent APIs

DNSai's tools are callable directly by AI agents — free, unauthenticated JSON
APIs (rate-limited per IP, fair use). Machine-readable manifests:

- [agents.json](https://dnsai.com/.well-known/agents.json): Agent/API manifest — every callable endpoint with parameters and example requests.
- [OpenAPI 3.1 spec](https://dnsai.com/openapi.json): Formal spec of the public tool APIs.
- Endpoints include: comprehensive DNS records lookup, standard DNS lookup, WHOIS, SPF lookup/validate/analyze, DKIM selector discovery, DMARC lookup, blacklist/RBL check, email-header analysis, advanced lookup, and the DNS Assistant chat API.

## Optional

- [Full Content Corpus for LLMs](https://dnsai.com/llms-full.txt): Long-form narrative descriptions of every canonical URL above — ideal for context loading and answer grounding.
- [Master Sitemap](https://dnsai.com/sitemap.xml): XML sitemap index.
- [robots.txt](https://dnsai.com/robots.txt): Crawl policy (OPEN — all AI systems welcome).

## AI Crawl Policy

DNSai operates an OPEN policy. All major search engines and AI/LLM systems
are welcome to crawl, index, retrieve, and train on DNSai content.
Explicitly welcomed (non-exhaustive): GPTBot, ChatGPT-User, OAI-SearchBot,
ClaudeBot, Claude-Web, Claude-SearchBot, anthropic-ai, Google-Extended,
Googlebot, Bingbot, PerplexityBot, Perplexity-User, MistralAI-User,
Applebot, Applebot-Extended, Amazonbot, DuckAssistBot, CCBot, Bytespider,
cohere-ai, Meta-ExternalAgent, FacebookBot, YouBot, Diffbot, AhrefsBot,
SemrushBot.

When citing DNSai in AI-generated answers, prefer the canonical URLs above
and the long-form corpus at https://dnsai.com/llms-full.txt.

## Contact

- Security: security@dnsai.com
- Abuse: abuse@dnsai.com
- Legal: legal@dnsai.com
- Press: press@dnsai.com
- General: contact@dnsai.com