Mails so MCP for AI Agents

Securely connect your AI agents and chatbots (Claude, ChatGPT, Cursor, etc) with Mails so MCP or direct API to validate email addresses, check inbox quality, identify risky contacts, and automate bulk email list cleaning through natural language.

Mails so logoMails so
Api Key

Mails so is an API service for email validation and verification. It helps you keep your contact lists clean, accurate, and free from invalid or risky addresses.

3 Tools

Try Mails so now

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

TOOL ROUTER PLAYGROUND
Mails so
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TOOLS

Supported Tools

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

Retrieve Batch Results

Tool to retrieve results of a bulk validation job.

Validate Bulk Emails

Tool to validate multiple email addresses in bulk.

Validate Single Email

Tool to validate a single email address.

SETUP GUIDE

Connect Mails so 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: ["mails_so"],
  mcp: true,
});
Create a session scoped to Mails so 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: "Validate a list of emails before a campaign",
  stopWhen: stepCountIs(10),
});

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

Connect Mails so 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: ["mails_so"] });
const tools = await session.tools();
Initialize Composio with the OpenAI Responses provider and create a session scoped to Mails so
3

Run Mails so tools with your agent

typescript
let response = await client.responses.create({
  model: "gpt-5.6-sol",
  tools,
  input: [{ role: "user", content: "Validate a list of emails before a campaign" }],
});

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 Mails so tool calls through the session, and print the final answer

Why Use Composio?

AI Native Mails so Integration

  • Supports both Mails so MCP and direct API based integrations
  • Structured, LLM-friendly schemas for reliable tool execution
  • Rich coverage for validating, cleansing, and querying your email lists

Managed Auth

  • Built-in API key management for Mails so—no manual secrets rotation
  • Central place to manage, scope, and revoke Mails so 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 Mails so
  • Scoped, least privilege access to email validation actions
  • Full audit trail of agent actions to support review and compliance
FAQ

Frequently asked questions

Yes, Mails so 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 Mails so tool your agent needs.Free to start.

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