Mailcheck MCP for AI Agents

Securely connect your AI agents and chatbots (Claude, ChatGPT, Cursor, etc) with Mailcheck MCP or direct API to verify email addresses, check deliverability, validate lists, and reduce bounces through natural language.

Mailcheck logoMailcheck
Api Key

Mailcheck is an email verification service that checks email validity in real time. It helps businesses reduce bounce rates and improve email deliverability.

2 Tools

Try Mailcheck now

Type what you want done — sign in and watch it run live in the Tool Router playground.

TOOL ROUTER PLAYGROUND
Mailcheck
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TOOLS

Supported Tools

Every Mailcheck action and event your agent gets out of the box.

Validate Domain

Tool to validate a domain for disposability, MX records, domain age, and spam indicators.

Verify Email Address

Tool to verify provided email address.

SETUP GUIDE

Connect Mailcheck MCP Tool with your Agent

1

Install Composio

typescript
npm install @composio/core ai @ai-sdk/mcp @ai-sdk/openai
Install the Composio SDK and your agent framework
2

Create a session with MCP enabled

typescript
import { Composio } from "@composio/core";

const composio = new Composio();
const { mcp } = await composio.create("your-user-id", {
  toolkits: ["mailcheck"],
  mcp: true,
});
Create a session scoped to Mailcheck and read its MCP URL and headers
3

Connect your agent to the MCP server

typescript
import { createMCPClient } from "@ai-sdk/mcp";
import { openai } from "@ai-sdk/openai";
import { generateText, stepCountIs } from "ai";

const client = await createMCPClient({
  transport: { type: "http", url: mcp.url, headers: mcp.headers },
});

const { text } = await generateText({
  model: openai("gpt-5.6-sol"),
  tools: await client.tools(),
  prompt: "Check if john.doe@email.com is a valid email address",
  stopWhen: stepCountIs(10),
});

console.log(text);
await client.close();
Pass the session's MCP URL and headers to your agent and run a Mailcheck request
SETUP GUIDE

Connect Mailcheck API Tool with your Agent

1

Install Composio

typescript
npm install @composio/core @composio/openai openai
Install the Composio SDK, the OpenAI provider, and the OpenAI SDK
2

Create a Composio session

typescript
import OpenAI from "openai";
import { Composio } from "@composio/core";
import { OpenAIResponsesProvider } from "@composio/openai";

const composio = new Composio({ provider: new OpenAIResponsesProvider() });
const client = new OpenAI();

const session = await composio.create("your-user-id", { toolkits: ["mailcheck"] });
const tools = await session.tools();
Initialize Composio with the OpenAI Responses provider and create a session scoped to Mailcheck
3

Run Mailcheck tools with your agent

typescript
let response = await client.responses.create({
  model: "gpt-5.6-sol",
  tools,
  input: [{ role: "user", content: "Check if john.doe@email.com is a valid email address" }],
});

while (response.output.some((o) => o.type === "function_call")) {
  const outputs = await composio.provider.handleToolCalls(session, response.output);
  response = await client.responses.create({
    model: "gpt-5.6-sol",
    tools,
    previous_response_id: response.id,
    input: outputs,
  });
}

console.log(response.output_text);
Send a request, execute the Mailcheck tool calls through the session, and print the final answer

Why Use Composio?

AI Native Mailcheck Integration

  • Supports both Mailcheck MCP and direct API based integrations
  • Structured, LLM-friendly schemas for reliable tool execution
  • Rich coverage for reading, writing, and querying your Mailcheck data

Managed Auth

  • Built-in OAuth handling with automatic token refresh and rotation
  • Central place to manage, scope, and revoke Mailcheck access
  • Per user and per environment credentials instead of hard-coded keys

Agent Optimized Design

  • Tools are tuned using real error and success rates to improve reliability over time
  • Comprehensive execution logs so you always know what ran, when, and on whose behalf

Enterprise Grade Security

  • Fine-grained RBAC so you control which agents and users can access Mailcheck
  • Scoped, least privilege access to Mailcheck resources
  • Full audit trail of agent actions to support review and compliance
FAQ

Frequently asked questions

Yes, Mailcheck requires you to configure your own API key credentials. Once set up, Composio handles secure credential storage and API request handling for you.

Yes! Composio's Tool Router enables agents to use multiple toolkits. Learn more.

Composio is SOC 2 and ISO 27001 compliant with all data encrypted in transit and at rest. Learn more.

Composio maintains and updates all toolkit integrations automatically, so your agents always work with the latest API versions.

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Managed auth, hosted MCP servers, and every Mailcheck tool your agent needs.Free to start.

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