Mailersend MCP server for AI agents and assistants

Securely connect your AI agents and chatbots (Claude, ChatGPT, Cursor, etc) with Mailersend MCP or direct API to send transactional emails, check delivery status, manage recipients, and fetch analytics through natural language.

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Api Key

MailerSend is a transactional email platform for developers to send, receive, and track emails via API. It provides reliable deliverability, analytics, and easy integration for your apps.

23 Tools

Try Mailersend now

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

TOOL ROUTER PLAYGROUND
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TOOLS

Supported Tools

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

Create Sending Domain

Tool to add a new sending domain to MailerSend.

Create SMTP User

Tool to create a new SMTP user.

Create API Token

Creates a new API token with specified scopes (permissions) for a domain.

Create Webhook

Tool to create a new webhook for a MailerSend domain.

Delete Webhook

Tool to delete an existing webhook.

Get API Quota

Tool to retrieve current API usage quota.

Get Domain

Tool to retrieve detailed information about a specific sending domain in MailerSend.

List Domain Recipients

Tool to list recipients for a domain.

Get sending domains

Retrieve a paginated list of all sending domains configured in your MailerSend account.

Get general API resources

Tool to retrieve general API resources and information.

List Sender Identities

Retrieves a paginated list of sender identities configured in your MailerSend account.

Get sent messages

Tool to retrieve a paginated list of sent messages.

Get email recipients

Tool to retrieve a list of email recipients.

Get SMS Activity

Tool to retrieve SMS activity logs.

Get SMS Inbounds

Retrieve inbound SMS route configurations.

List SMS Messages

Retrieves a paginated list of SMS messages sent through the MailerSend API.

Get SMS Numbers

Tool to retrieve a paginated list of SMS phone numbers.

Get SMS recipients

Tool to retrieve a list of SMS recipients.

Get SMTP users

Tool to retrieve a list of SMTP users.

Get email templates

Retrieves a paginated list of email templates from your MailerSend account.

Get API Tokens

Retrieves a paginated list of API tokens associated with your MailerSend account.

Get users

Tool to retrieve a list of users associated with your account.

List webhooks

Tool to retrieve a list of webhooks.

SETUP GUIDE

Connect Mailersend 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: ["mailersend"],
  mcp: true,
});
Create a session scoped to Mailersend 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: "Send a welcome email to a new user",
  stopWhen: stepCountIs(10),
});

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

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

Run Mailersend tools with your agent

typescript
let response = await client.responses.create({
  model: "gpt-5.6-sol",
  tools,
  input: [{ role: "user", content: "Send a welcome email to a new user" }],
});

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 Mailersend tool calls through the session, and print the final answer

Why Use Composio?

AI Native Mailersend Integration

  • Supports both Mailersend MCP and direct API based integrations
  • Structured, LLM-friendly schemas for reliable tool execution
  • Rich coverage for sending, fetching, and querying Mailersend emails

Managed Auth

  • Built-in API key handling and secure storage
  • Central place to manage, scope, and rotate Mailersend 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 Mailersend
  • Scoped, least privilege access to Mailersend resources
  • Full audit trail of agent actions to support review and compliance

Rolling this out across your team?

Give your team centralized access control across every framework with Composio’s MCP Gateway.

EXPLORE MCP GATEWAY
FAQ

Frequently asked questions

Yes, Mailersend requires you to configure your own API key. 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.

Yes. Composio is SOC 2 Type II compliant and is built to keep your Mailersend connection and credentials secure. OAuth tokens and API keys are encrypted, and sensitive customer data is protected at rest and in transit.

Composio also undergoes independent security testing and continuously monitors its systems for security threats. You can review the latest reports and policies in the Composio Trust Center.

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

Create the key in your Mailersend account settings, then paste it once on Composio's connection page. Composio stores it encrypted and uses it only for the Mailersend actions your agent runs. Nobody else in your workspace can read it, and you can revoke it inside Mailersend at any time.

When you connect a Mailersend account through Composio, every action runs under that account, so anything the agent creates, sends, or changes shows up in Mailersend as done by you. Keep an approval step in your prompt for actions with side effects, such as sending or deleting, and have the agent draft first.

Whatever the credentials you connect allow inside Mailersend. If Mailersend lets you scope a key to specific permissions, create a scoped one so the agent can only do what you intend. You can revoke the key inside Mailersend at any time.

Yes. Composio supports multiple connected accounts for the same app, and that works in Claude, ChatGPT, or any other assistant you connect through Composio. Give each Mailersend connection a name such as work or personal, and the assistant uses the one you mention in the request. Each account keeps its own credentials and nothing is merged.

The connection stops working the moment Mailersend rejects the old key. Create a new key in Mailersend and reconnect the account from the Composio dashboard or by asking your agent to reconnect Mailersend. Nothing else changes.

Composio's free Hobby plan includes 100,000 tool calls per month with no credit card, which covers most personal Mailersend use. Paid plans add higher limits and team features. Your Mailersend plan and its API limits still apply as usual.

Built-in connectors usually give one AI access to a limited set of apps. Many people use Composio because it lets their AI connect to more apps than it normally supports, or connect to multiple accounts for the same app (e.g. connect Claude to multiple Mailersend accounts).

With Composio, you connect Mailersend once and then use it across different AI assistants without setting it up separately in each one. Connect your apps to Composio once, then connect Composio to whichever AI you use, whether that's Claude, ChatGPT, Hermes, or your own custom assistant.

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