Email Verification Grounding Data

Overview

An email verification API and email checker for signup forms and CRM imports. Email Validator checks the address format, resolves the domain's MX records, follows the RFC fallback to the domain's A record, flags domains that publish a null MX, and reports whether the domain has SPF and DMARC records. It matches the domain against free, disposable and role-account lists, and returns a normalized address so +tag and Gmail-dot variants collapse to one. Every check runs over DNS, with no SMTP mailbox probe, so a slow mail server never holds up the response. Paid plans add a risk score and a suggested correction for domain typos.

Live Test Email Verification Grounding Data Source →

The tool

Once your client is connected to the VerveContext server, this appears in its tool list as EmailVerificationGroundingData. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

{
  "name": "EmailVerificationGroundingData",
  "arguments": {
    "email": "[email protected]"
  }
}

You do not name the tool yourself; the model picks it. Asking about [email protected] in the terms this source covers is enough for it to reach for EmailVerificationGroundingData on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every source in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervecontext": {
      "url": "https://api.vervecontext.com/v1/mcp"
    }
  }
}

https://api.vervecontext.com/v1/mcp

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

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{
  "status": "ok",
  "error": null,
  "data": {
    "email": "[email protected]",
    "domain": "myspace.com",
    "username": "support",
    "isRegexValid": true,
    "hasTypo": false,
    "isMxValid": true,
    "isValid": true,
    "isFreeEmail": false,
    "isCompanyEmail": true,
    "isDisposable": false,
    "isRoleAccount": true,
    "mxRecord": "mxa-00ac0e01.gslb.pphosted.com",
    "isNullMx": false,
    "canReceiveMail": true,
    "hasSpf": true,
    "hasDmarc": true,
    "isSubaddressed": false,
    "normalizedEmail": "[email protected]",
    "suggestedCorrection": null,
    "mailProvider": "Proofpoint",
    "isSecurityGateway": true,
    "roleCategory": "support",
    "riskScore": 10,
    "riskLevel": "low"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Why ground on it

A model can produce something that looks like this answer from its training data, and be confidently out of date or simply wrong. This source returns the current value in a shape you can check, which is the difference between an answer you can cite and one you have to hedge.

Point an evaluation at domain: it is the field most worth pinning a claim to, and it is either present and current or absent — never plausibly invented.

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

A call costs 20 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Signup Abuse Prevention

To stop fake signups, SaaS onboarding flows block temporary addresses by checking disposable flags before creating new trial accounts.

B2B Lead Routing

Sales teams verify company domains against free provider flags to route corporate inquiries directly to account executives.

Mailing List Hygiene

When scrubbing subscriber databases, email marketers filter out missing mail records and invalid syntax to protect sender reputation.

Customer Support Routing

Flag shared inboxes like billing or support addresses during ticket submission to direct automated receipts to named team members instead.

Free Trial Abuse

Store the normalized address at signup so [email protected] and [email protected] count as one person when a product hands out free trials or credits.

Other ways to use Email Verification Grounding Data

Set up Email Verification Grounding Data on VerveContext, or reach the same source a different way. Your VerveContext account and credits work on all of them — one key, one balance.

Related

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