SPF, DKIM & DMARC Checker (Bulk Domain Email Authentication Audit)

Price: $3 per 1,000 domains ($0.003 per domain checked). Errors, non-existent domains and unchanged domains are free.

Check the email authentication of hundreds or thousands of domains in one run. For every domain the actor reads public DNS and returns:

• SPF: record, all qualifier (-all, ~all...), number of DNS lookups (RFC 7208 limit of 10, includes followed recursively), includes, duplicates, deprecated ptr.
• DMARC: record, policy (p), subdomain policy (sp), pct, aggregate (rua) and forensic (ruf) report addresses, alignment (adkim, aspf), inherited policy from the parent domain.
• DKIM: tests ~45 common selectors (Google Workspace, Microsoft 365, Mailchimp/Mandrill, SendGrid, Zoho, Proton, Fastmail, Mailjet, HubSpot, iCloud...) plus your own; key type, key size, revoked keys, test mode.
• MX: records, priorities, detected mail provider (Google, Microsoft 365, Proofpoint, Mimecast...), null MX.
• BIMI (logo and VMC URLs), MTA-STS and TLS-RPT.
• A score (0-100) and grade (A-F), a list of issues by severity and concrete fixes in plain English, plus a ready-to-paste Markdown summary for reports and LLMs.
• Change monitoring: schedule it and get only the domains whose SPF, DMARC, DKIM or MX changed.

No API key, no login, no website scraping: everything is read from public DNS over HTTPS, so results are fast and reliable.

How much does it cost?

Pay per result, no monthly rental. One event domain-checked = $0.003.

Domains	Price
100	$0.30
1,000	$3.00
10,000	$30.00

Not charged: invalid inputs, duplicates, domains that do not exist (NXDOMAIN), DNS errors, and domains skipped as unchanged in onlyChanges mode. You can set a maximum spend per run; the actor stops cleanly when it is reached.

Input

{
  "domains": ["stripe.com", "example.org", "john@acme-corp.com", "https://www.shopify.com/pricing"],
  "dkimSelectors": ["s2048"],
  "checkCommonDkimSelectors": true,
  "monitorChanges": false,
  "onlyChanges": false,
  "monitorName": "default",
  "maxConcurrency": 8
}

• domains (required): domains, email addresses or URLs. IDN (bücher.de) supported. Duplicates are checked once.
• dkimSelectors: your own selectors (look for s= in the DKIM-Signature header of an email you sent).
• monitorChanges: keep a snapshot between runs and add changed / changes to each result.
• onlyChanges: output and charge only new or changed domains (for scheduled runs).
• monitorName: separate saved states, e.g. one per client.

Output

One object per domain in the dataset (shortened example):

{
  "domain": "stripe.com",
  "inputValue": "stripe.com",
  "score": 93,
  "grade": "A",
  "spfRecord": "v=spf1 include:_spf.google.com include:mail.stripe.com ... ~all",
  "spfValid": true,
  "spfAllQualifier": "~all",
  "spfDnsLookups": 9,
  "spfIncludes": ["_spf.google.com", "mail.stripe.com"],
  "dmarcRecord": "v=DMARC1; p=reject; pct=100; fo=1; rua=mailto:...; ruf=mailto:...",
  "dmarcPolicy": "reject",
  "dmarcPct": 100,
  "dmarcRua": ["mailto:dmarc@stripe.com"],
  "dkimSelectorsFound": ["google"],
  "dkimKeys": [{"selector": "google", "keyType": "rsa", "keyBits": 2048, "revoked": false, "testMode": false, "record": "v=DKIM1; k=rsa; p=MIIB..."}],
  "mxRecords": [{"priority": 1, "host": "aspmx.l.google.com"}],
  "mxProvider": "Google Workspace",
  "nullMx": false,
  "bimiRecord": null,
  "mtaStsRecord": "v=STSv1; id=...",
  "tlsRptRecord": null,
  "issues": [{"severity": "info", "area": "SPF", "message": "..."}],
  "recommendations": ["Your DMARC policy qualifies for BIMI: publish default._bimi with your SVG logo."],
  "summaryMarkdown": "## stripe.com — email authentication grade A (93/100)\n- SPF: ...",
  "isNew": null,
  "changed": null,
  "changes": null,
  "checkedAt": "2026-10-21T08:00:00+00:00"
}

Values above are illustrative; the actor returns the live DNS values. In the Console, the Overview table shows domain, grade, score, SPF, DMARC, DKIM, provider and fixes; export as JSON, CSV, Excel or HTML.

With monitoring on, a changed domain looks like:

{"domain": "acme-corp.com", "changed": true, "changes": [{"field": "dmarcRecord", "previous": "v=DMARC1; p=none; rua=mailto:d@acme-corp.com", "current": "v=DMARC1; p=quarantine; rua=mailto:d@acme-corp.com"}]}

Use cases

1. MSP / IT provider: weekly audit of all client domains

An MSP manages 120 client domains and must catch broken SPF (more than 10 lookups after adding a new SaaS) before mail starts bouncing. Every Monday a schedule runs:

{"domains": ["client-a.com", "client-b.fr", "client-c.de"], "monitorChanges": true, "onlyChanges": true, "monitorName": "msp-clients"}

Output: only the domains that changed, e.g. {"domain": "client-b.fr", "changed": true, "spfDnsLookups": 12, "spfValid": false, "recommendations": ["Reduce SPF DNS lookups to 10 or fewer..."]}. A Make scenario sends each changed domain to the ticketing tool. Cost for a typical week (5 changes): $0.015.

2. Cold-email / deliverability agency: pre-flight check of sending domains

Before warming up 40 new sending domains, an agency checks they all have SPF, DKIM and DMARC with reports:

{"domains": ["getacme.io", "tryacme.io", "acmehq.co"], "dkimSelectors": ["s1", "google"]}

Output: {"domain": "tryacme.io", "grade": "D", "dmarcRecord": null, "dkimSelectorsFound": [], "recommendations": ["Publish a DMARC TXT record at _dmarc.tryacme.io ...", "Enable DKIM signing ..."]}. The team filters grade != "A" in Google Sheets and fixes those domains first. 40 domains = $0.12.

3. Sales / lead generation: security posture of 10,000 prospects

A security vendor selling DMARC services scores a prospect list exported from the CRM:

{"domains": ["prospect1.com", "prospect2.com", "..."], "maxConcurrency": 20}

Output: {"domain": "prospect2.com", "dmarcPolicy": "none", "dmarcRua": [], "mxProvider": "Microsoft 365", "score": 48}. Prospects with dmarcPolicy none or missing go into an outreach sequence personalized with summaryMarkdown. 10,000 domains = $30.

4. Security team: brand protection on look-alike and parked domains

Parked domains should send nothing: SPF v=spf1 -all, DMARC p=reject, null MX. Input the 300 defensive registrations and keep those not graded A.

Call it from the API

Python:

from apify_client import ApifyClient

client = ApifyClient("<APIFY_TOKEN>")
run = client.actor("<USERNAME>/email-dns-auth-checker").call(run_input={"domains": ["stripe.com", "example.org"]})
for item in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(item["domain"], item["grade"], item["dmarcPolicy"], item["recommendations"])

JavaScript:

import { ApifyClient } from 'apify-client';

const client = new ApifyClient({ token: '<APIFY_TOKEN>' });
const run = await client.actor('<USERNAME>/email-dns-auth-checker').call({ domains: ['stripe.com', 'example.org'] });
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((i) => console.log(i.domain, i.grade, i.spfDnsLookups));

Synchronous HTTP (small lists): POST https://api.apify.com/v2/acts/<USERNAME>~email-dns-auth-checker/run-sync-get-dataset-items?token=<APIFY_TOKEN> with the input JSON as body.

Integrations (Make, Zapier, n8n, Google Sheets)

• n8n / Make: "Run actor" node with {"domains": {{ $json.domains }}, "monitorChanges": true, "onlyChanges": true}, then "Get dataset items", then filter changed = true and post to Slack or e-mail.
• Zapier: trigger "New row in Google Sheets" → Apify "Run actor" with the domain → write grade and recommendations back to the row.
• Google Sheets: use the Apify Google Sheets integration on the run to export the Overview view directly.
• Schedules: Apify Console → Schedules → weekly run with onlyChanges: true for DNS change alerts.

Use with AI agents (MCP)

The actor works as a tool for Claude, Cursor, ChatGPT and other agents through the Apify MCP server (https://mcp.apify.com, add the actor email-dns-auth-checker). An agent can ask "Is acme.com protected against spoofing?" and get structured JSON plus summaryMarkdown, a short Markdown report with numbered fixes that can be quoted directly in an answer.

FAQ

How is DKIM found? DKIM keys live at <selector>._domainkey.<domain> and DNS cannot list selectors. The actor tests ~45 common selectors; if you use a custom one, add it in dkimSelectors. "No DKIM found" is reported as info, not as proof that DKIM is missing.

Which DNS servers are used? Public DNS-over-HTTPS resolvers (Google, with Cloudflare as fallback, with retries). Results reflect what the internet sees, not your local cache.

Does it send emails or connect to mail servers? No. It only reads public DNS records. No SMTP connection, no login.

How is the score computed? SPF 25 points, DMARC 35 (reject > quarantine > none, rua), DKIM 20 (2048-bit key gets full points), MX 10, BIMI/MTA-STS/TLS-RPT 10. Domains that send no email (null MX or v=spf1 -all) are not penalized for missing DKIM or BIMI.

What about subdomains? If a subdomain has no DMARC record, the actor walks up to the parent domain and reports the inherited policy (dmarcSource).

Is a domain without MX an error? No, it is a valid result (charged) with an MX issue. Only non-existent domains are free.

Limits

• DKIM detection is limited to common and user-supplied selectors.
• The MTA-STS policy file (HTTPS) is not downloaded; only the _mta-sts TXT record is checked. BIMI logos and VMC certificates are not validated.
• Organizational domain detection walks up DNS labels without the Public Suffix List; for rare multi-level suffixes the inherited DMARC source may differ from what a receiver uses.
• SPF lookup counting follows include and redirect up to 10 levels; macros (%{...}) are not expanded.
• DNS answers can be cached by resolvers for the record TTL: a change you just made may appear on the next run.