Website & Email Domain Checker: SSL, DNS, MX, SPF, DMARC, DKIM

Bulk domain checker API: SSL certificate expiry, SPF, DMARC, DKIM, MX email provider, HTTP status and tech stack for a list of domains. One JSON row per domain, $0.008 per domain, invalid domains free.

Bulk-check any list of domains or URLs in one run and get one clean JSON record per domain:

• Website health: HTTP status, full redirect chain, final URL, HTTPS enforcement, response time. Plain-HTTP-only sites work too (automatic https → http fallback, flagged as plainHttpOnly)
• SSL/TLS certificate: valid or not, issuer, expiry date and days left, TLS version
• Security headers: HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, COOP, with a 0–100 score
• Email setup: does the domain receive mail (MX records), which email provider (Google Workspace, Microsoft 365, Zoho, Proofpoint…), SPF, DMARC policy, DKIM (common selectors probed), and an A–F email-authentication grade
• Tech stack hints (fingerprints): CDN/hosting (Cloudflare, CloudFront, Vercel, Netlify…), CMS (WordPress, Shopify, Wix, Webflow…), frameworks and analytics tags
• AI readiness: which AI crawlers (GPTBot, ClaudeBot, PerplexityBot, Google-Extended…) robots.txt blocks, and whether /llms.txt exists
• DNS: A/AAAA, NS, CAA, TXT domain-verification hints (Google, Microsoft, Atlassian, Stripe…)

Public data only: DNS queries, one TLS handshake, the homepage, robots.txt and llms.txt. No logins, no personal data, no scraping behind walls.

Use cases

• Sales and GTM teams, Clay, n8n and Make users: qualify leads by email provider, tech stack and whether the website is alive.
• Agencies and freelancers: instant website and email-deliverability audit for prospects ("your DMARC is missing, your SSL expires in 9 days").
• IT, security and deliverability teams: monitor SSL expiry and SPF/DMARC/DKIM across many domains on a schedule.
• AI agents (MCP): a cheap, fast tool for "check this domain's email security / SSL / tech stack".

Input

Field	Type	Default	Notes
domains	array of strings	— (required)	Domains or URLs. Duplicates removed.
maxDomains	integer	1000	Budget guard.
checkDkim	boolean	true	Probes ~19 common DKIM selectors.
dkimSelectors	array	—	Replace the default selector list.
checkRobots	boolean	true	AI-crawler policy and llms.txt.
dnsResolver	doh / system	doh	DNS-over-HTTPS (Cloudflare, Google fallback) or the container resolver.
timeoutSecs	integer	15	Hard limit per HTTP/TLS request (connect + response). Each domain also has an overall cap, so one slow site never stalls the run.
maxConcurrency	integer	10	Parallel domains (max 50).

Example input:

{ "domains": ["stripe.com", "https://www.github.com/features", "example.com"], "maxConcurrency": 10 }

Output (one item per domain)

Each item has summary (flat, spreadsheet-friendly), plus website, ssl, dns, email and errors. Trimmed example from a real run (stripe.com, 3 Nov 2026; live values change over time):

{
  "domain": "stripe.com",
  "ok": true,
  "summary": { "resolves": true, "websiteUp": true, "sslValid": true, "sslDaysLeft": 187, "mailConfigured": true,
               "mailProvider": "Google Workspace", "emailAuthGrade": "A", "securityHeadersScore": 86, "responseTimeMs": 2535 },
  "website": { "finalUrl": "https://stripe.com/in", "finalStatus": 200, "redirectCount": 1, "httpsEnforced": true,
               "techHints": ["Next.js", "nginx"], "robots": { "aiCrawlersBlocked": [] }, "llmsTxt": { "present": true } },
  "ssl": { "valid": true, "issuer": "DigiCert, Inc.", "validTo": "2027-05-09T23:59:59.000Z", "daysUntilExpiry": 187, "protocol": "TLSv1.3" },
  "email": { "hasMailSetup": true, "provider": "Google Workspace", "spf": { "allQualifier": "~" }, "dmarc": { "policy": "reject" },
             "dkim": { "selectorsFound": ["google", "mandrill", "s1", "s2"] }, "authGrade": "A" }
}

More examples: samples/input.example.json, samples/output.sample.json (full run on 9 inputs, including invalid and non-existent domains).

Export as JSON, CSV, Excel, or use the Overview table view.

Pricing (pay per event)

• $0.008 per domain checked (domain-checked event) — $8 per 1,000 domains.
• Invalid inputs and domains that do not resolve are free (pushed with an error, not charged).
• The run stops cleanly when your spending limit is reached.

Limits and accuracy notes

• DKIM: DNS cannot list DKIM selectors; common ones are probed. "No selector found" does not prove DKIM is absent. Wildcard _domainkey records are detected and ignored.
• Tech hints are lightweight fingerprints from headers and homepage HTML, not a full BuiltWith-style crawl.
• Response time is measured from the Actor's server location.
• Only the homepage, robots.txt and llms.txt are fetched. It is not a site crawler or a vulnerability scanner.
• Sites that block datacenter traffic or rate-limit may show errors or different status codes than in your browser.
• emailAuthGrade is a simple score: SPF (35), DMARC policy (40), DKIM found (25).

How it compares

• vs. a plain DNS or SPF/DMARC lookup tool: those return DNS records only, and some cost less per domain. This Actor also does a TLS handshake (certificate expiry, issuer, TLS version), fetches the homepage (status, redirects, HTTPS enforcement, response time, security headers, tech hints) and reads robots.txt / llms.txt. If you only need DNS records, a DNS-only tool may be the cheaper choice.
• vs. BuiltWith or Wappalyzer: tech hints here are light fingerprints from one homepage, not a full technology profile. Use those tools if tech detection is your main need.
• vs. a vulnerability scanner: this is not one. It reads public records and one page and does not probe for weaknesses.

Schedule it (SSL and email-auth monitoring)

1. Save your domain list as a Task in Apify Console.
2. Add an Apify Schedule (for example every Monday 09:00).
3. In your integration, alert when summary.sslDaysLeft < 21, summary.emailAuthGrade is D or F, or summary.websiteUp is false.

Keep checkDkim: false on very large lists if you want faster runs.

Use in Clay, n8n, Make or any HTTP tool

Any HTTP tool (one call, results in the response):

POST https://api.apify.com/v2/acts/damodaran_dhanuauraman~website-email-domain-checker/run-sync-get-dataset-items?token=<YOUR_APIFY_TOKEN>
Content-Type: application/json
{ "domains": ["example.com", "stripe.com"], "checkDkim": false }

Clay: add an Apify enrichment ("Run Apify Actor"), choose damodaran_dhanuauraman/website-email-domain-checker, set the input to {"domains": ["<Company Domain column>"], "checkDkim": false}, then map summary.mailProvider, summary.emailAuthGrade, summary.websiteUp, summary.sslDaysLeft and website.techHints. Skip rows without a domain. Rows with an invalid domain are not charged.

n8n / Make: Schedule trigger → read domains (e.g. Google Sheets) → Apify "Run Actor" (or the HTTP request above) → filter on the summary fields → Slack or email alert.

Use with AI agents, API and integrations

Call it from the Apify API, the Apify MCP server (tool name follows the Actor name), Clay, n8n, Make or Zapier. Typical agent prompt: "Check the SSL expiry, email provider and DMARC policy of these 50 domains." Schedule it daily or weekly to monitor SSL expiry and email-auth changes.

Feedback

Found a wrong result? Open an issue in the Issues tab with the domain and the field that looks wrong.

FAQ

Is this legal? It only reads public DNS records and public web pages, the same as any browser or dig. Does it collect personal data? No. It returns technical records about domains only. How much does a run cost? $0.008 per domain that resolves. 100 domains = $0.80. Invalid and non-resolving domains are free. How fast is it? Usually a few seconds per domain, 10 in parallel by default (up to 50). Can it watch for changes? Run it on a schedule and compare summary fields between runs in your sheet or workflow. It does not store history itself. Can I check subdomains? Yes. The host you enter is fetched; email checks run on the registrable domain with www. stripped.

Keywords: SSL certificate checker, SSL expiry monitor, DMARC checker, SPF checker, DKIM lookup, MX lookup, email provider lookup, domain checker, website status checker, redirect checker, security headers scanner, tech stack lookup, BuiltWith alternative, Wappalyzer alternative, llms.txt checker, AI crawler robots.txt checker.