Email Verifier MCP Server

An MCP server for the Mamba Labs Email List Verifier, Bring Your Own Key actor on Apify. Give it a list of email addresses and it checks each one with the verification service you already pay for: ZeroBounce, NeverBounce, MillionVerifier, BounceBan, or Reoon Email Verifier. You supply the service key.

What's Inside

What it does
Quick start
Prerequisites
Example prompts
Tool
Inputs
Pricing
Your key
Full actor documentation
License

What it does

One flat row per address: verdict (valid, invalid, catch_all, risky, or unknown), the service's own provider_status and provider_sub_status, is_role, is_free_email, is_disposable, and did_you_mean for a spelling fix.
One layout for every service: the five services spell their answers differently; every row uses the same five verdicts and the same columns.
Credits protected: an address with broken syntax is never sent, a repeat is checked once, and a rejected key or an empty service balance stops the run from sending more.

Bad input returns one free row whose error_reason starts with input_invalid:. With no key set, the tool refuses before any run starts, so nothing is charged.

All of the work runs on Apify. This package is a thin client that starts the actor run, waits for it, and hands back the dataset rows.

Quick start

You need Node.js 18 or newer, an Apify account with an API token, and an API key for one of the five services.

Add this to your Claude Desktop config (claude_desktop_config.json), Cursor, or any MCP client:

{
  "mcpServers": {
    "mamba-email-verifier": {
      "command": "npx",
      "args": [
        "-y",
        "@mambalabsdev/mcp-email-verifier"
      ],
      "env": {
        "APIFY_TOKEN": "your-apify-token",
        "EMAIL_VERIFIER_API_KEY": "your-verification-service-key"
      }
    }
  }
}

Restart the client. The verify_emails tool appears.

Prerequisites

Node.js 18 or newer.
An Apify API token from console.apify.com/account/integrations, set as APIFY_TOKEN. The server lists its tool without a token; a call needs one.
Your own API key for ZeroBounce, NeverBounce, MillionVerifier, BounceBan, or Reoon Email Verifier, set as EMAIL_VERIFIER_API_KEY.

Example prompts

"Verify these 40 addresses with my NeverBounce key and list the ones that are not valid."
"Which of these leads are catch all or role addresses?"
"Check [email protected] and tell me if the domain looks like a typo."

Tool

verify_emails. One tool. Example arguments:

{
  "emails": [
    "[email protected]",
    "[email protected]"
  ],
  "provider": "neverbounce"
}

Inputs

Every buyer facing input of the actor except api_key, which comes from EMAIL_VERIFIER_API_KEY in the server environment so it never passes through the conversation. Omitted inputs take the actor's own defaults. Numbers are sent as strings.

Input	Type	Description
`emails`	array	Required. The addresses to verify, 1 to 5,000 per run
`email`	string	One more address, added to `emails`
`provider`	string	zerobounce (default), neverbounce, millionverifier, bounceban, or reoon. The service your key belongs to
`concurrency`	string	Addresses checked at the same time, 1 to 20. Default 5
`max_charge_usd`	string	Optional. The run stops before an actor charge that would pass this amount

Pricing

Two separate bills. Your verification service bills each check to your account there, at your plan's price. The actor charges per event on Apify, billed to your Apify account. Prices in USD.

Event	Free plan	Bronze	Silver	Gold
`email-verified`, one address your service answered valid, invalid, catch all, or risky	$0.0016	$0.00152	$0.00144	$0.00136
`apify-actor-start`, per run start	$0.0006	$0.0006	$0.0006	$0.0006

Unknown answers, error rows, addresses with broken syntax, repeats in the same run, and refused input are free. Mamba Labs pays the Apify platform costs of the run.

Your key

The key is read from this server's environment and passed in the run input as a secret field. The actor sends it only to the service you chose and never logs, stores, or returns it. Apify blocks the outbound mail port, so every mailbox check runs at your service.

Full actor documentation

apify.com/mambalabs/email-verifier

License

MIT. See LICENSE.

Email Verifier MCP Server