Email Validator for Agents (MX, Disposable, Typo)

Fairquery Apify Actor that validates email addresses without sending any email or probing SMTP servers: syntax, DNS/MX, null MX, disposable-domain and role-account detection, free-provider flag, typo suggestions (“gmial.com” → “gmail.com”), mail provider, and SPF/DMARC. Each address gets a clear valid / risky / invalid / unknown verdict with machine-readable reason codes.

When to use this Actor (LLM / tool selection)

Use it when an agent needs to:

• Clean a lead / CRM / signup list before outreach or import
• Decide whether an address can receive mail (domain exists, has MX, no null MX)
• Flag disposable/temporary inboxes, role addresses (info@, sales@) or free webmail on B2B forms
• Suggest a fix for a mistyped domain
• See which mail provider (Google Workspace, Microsoft 365, …) and DMARC policy a domain uses

Do not use it to confirm a specific mailbox exists — that requires SMTP probing, which this Actor deliberately avoids (privacy, IP reputation and ToS reasons). valid means “well-formed, deliverable domain, no risk flags”, not “mailbox confirmed”.

How it works

Input

{ "emails": ["[email protected]", "[email protected]", "[email protected]"], "allowFreeProviders": false }

Output

Every row has schema_version (1.0.0), type (email | error), source_url (the DoH MX query URL), checked_at.

{
  "type": "email", "input": "[email protected]", "email": "[email protected]", "domain": "gmial.com",
  "verdict": "risky", "reasons": ["DISPOSABLE_DOMAIN", "POSSIBLE_TYPO", "IMPLICIT_MX_ONLY"],
  "syntax_valid": true, "is_disposable": true, "is_role_account": false, "is_free_provider": false,
  "did_you_mean": "[email protected]", "domain_exists": true, "has_mx": false, "null_mx": false,
  "implicit_mx": true, "mx_records": [], "mail_provider": null, "has_spf": false, "has_dmarc": false, "dmarc_policy": null,
  "source_url": "https://cloudflare-dns.com/dns-query?name=gmial.com&type=MX"
}

Reason codes: INVALID_SYNTAX, DOMAIN_NOT_FOUND, NULL_MX, NO_MAIL_SERVER (→ invalid); DISPOSABLE_DOMAIN, ROLE_ACCOUNT, FREE_PROVIDER, POSSIBLE_TYPO, IMPLICIT_MX_ONLY (→ risky depending on the allow* flags); DNS_NOT_CHECKED (→ unknown).

Error rows (machine-readable, never charged)

{ "type": "error", "code": "DNS_LOOKUP_FAILED", "message": "DoH MX acme.com -> HTTP 503", "retryable": true, "input": "[email protected]", "domain": "acme.com" }

Codes: INPUT_EMPTY, MAX_EMAILS_EXCEEDED, DNS_LOOKUP_FAILED. Duplicate addresses (case-insensitive) are skipped and counted in the summary.

Run summary

Key-value store record RUN_SUMMARY: emails checked, duplicates skipped, verdict counts, domains checked, DNS request count, echoed input.

Pricing

Pay per event: email-checked per email row. Error rows are never charged. See the Store pricing tab.

Memory / runtime

Default 256 MB. No browser, no proxy. ~1,000 emails across a few hundred domains finish in well under a minute.

MCP / Apify tools

Call from agents via Apify MCP (https://mcp.apify.com, authenticated with your Apify token), Actor fairquery/email-validator-mx-disposable:

{ "actor": "fairquery/email-validator-mx-disposable", "input": { "emails": ["[email protected]"] } }

Read dataset items (type == "email") and the RUN_SUMMARY record. A standalone stdio MCP server lives in the GitHub repo under mcp/.

Local stdio MCP server

This repo ships a stdio MCP server (TypeScript, @modelcontextprotocol/sdk) under mcp/ exposing validate_emails (runs this Actor through the Apify API) and the free offline check_email_syntax. initialize and tools/list work without a token; tool calls require APIFY_TOKEN (billed per the Store pricing).

cd mcp && npm install && npm run build
node scripts/smoke-test.mjs                          # initialize + tools/list, no token
APIFY_TOKEN=... node scripts/smoke-test.mjs --call   # real tool call

{ "mcpServers": { "fairquery-email": { "command": "node", "args": ["/path/to/email-validator-mx-disposable/mcp/dist/index.js"], "env": { "APIFY_TOKEN": "" } } } }

Docker: docker build -t fairquery-email-mcp . (the repo-root Dockerfile builds this MCP server and is what Glama uses; the Apify Actor image is built from .actor/Dockerfile). glama.json lists fairquery as maintainer.

Links

• Apify Store: https://apify.com/fairquery/email-validator-mx-disposable
• License: MIT

Local development

npm install
npx apify run      # uses input defaults, or storage/key_value_stores/default/INPUT.json
npm test

Kits & templates

Optional guides from Fairquery for wiring this Actor into agents and automations (the Actor works fine without them):

• AI Agent Data Toolkit Quick-Start (PDF): MCP setup for Claude Desktop and Cursor, API calls, recipes, cost estimates.
• n8n + Zapier Workflow Template Pack: 10 importable n8n workflows for the four Fairquery Actors, plus Zapier setup guides.
• Agent Prompt Pack for Research & Lead Ops: 69 prompts for company research, lead cleaning, SEO and security reviews.
• Agent Starter Kit: 10 copy-paste MCP + n8n recipes ($5): 10 copy-paste MCP + n8n recipes, with ready-made Claude/Cursor configs and 3 starter workflows.

Disclaimer

DNS-based validation cannot guarantee a mailbox exists or accepts mail. Use results to reduce bounces, not as proof of deliverability. Comply with anti-spam law (CAN-SPAM, GDPR/ePrivacy) when emailing.