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How to connect Mailtrap to Claude

Connect Claude Web, Desktop and Cowork to Mailtrap MCP. Send a test email to marketing team, list all emails sent from mailtrap today, and more using natural language, with authentication handled for you.

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Mailtrap is an email delivery platform for safe email testing and transactional email sending. It helps you catch bugs and verify email flows without spamming real inboxes.

49 Tools

Introduction

Claude is Anthropic's AI assistant, available on the web, in the desktop app, and on mobile. Cowork is its agent for knowledge work, and it runs on all of those surfaces too. Connected to your apps, Claude can work with your files and services to accomplish complex tasks on your behalf.

This guide walks you through the easiest and most secure way to connect your Mailtrap account to Claude via Composio Connect, enabling it to send a test email to marketing team, list all emails sent from Mailtrap today, create a new inbox for transactional testing, and more such actions on your behalf without compromising your account security.

Setup is the same on Claude Web, Desktop, and Cowork, and you only need to do it once. The connector is tied to your account, so it's available in all three.

Also integrate Mailtrap with

Claude CodeCursorChatGPTAntigravityOpenAI Agents SDKClaude Agent SDKCodexGrok BuildVS CodeOpenCodeOpenClawHermesAtomic AgentGoogle ADKLangChainVercel AI SDKMastra AILlamaIndexCrewAIPydantic AIAutoGen

Connecting Mailtrap to Claude Web, Desktop, and Cowork

Two ways to add the Composio connector. Pick whichever you prefer.

1. Add with one click

Click the button. Claude opens with the Composio connector filled in. Click Add, then go to step 2.

Add to Claude

Add manually

In Claude Desktop, click Customize in the left sidebar, then select Connectors and click the + icon at the top.

Claude Desktop connectors screen with Add custom connector selected

Click Add custom connector and paste in the Composio MCP server URL:

bash
https://connect.composio.dev/mcp
Add custom connector dialog with Composio MCP server URL

2. Authorize in your browser

Click Connect. You'll be redirected to a browser window where you can authorize Composio to continue.

Composio authorization screen for Claude Web, Desktop, and Cowork

3. Connect your Mailtrap account

Back in Claude, ask it to connect to Mailtrap or give it any Mailtrap-related task.

For example, ask Claude to:

  • "Send a test email to marketing team"
  • "List all emails sent from Mailtrap today"
  • "Create a new inbox for transactional testing"

It will prompt you to authenticate and authorize access.

That's it. Composio's tools are now available in Claude, and your Mailtrap account is ready to use.

What is the Mailtrap Claude Connector, and what's possible with it?

The Mailtrap MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Mailtrap account. It provides structured and secure access so your agent can perform Mailtrap operations on your behalf.

Troubleshooting

1. Why does Claude not use the Composio connector for Mailtrap?

The connector can show as connected, but Claude must use it in each Mailtrap conversation.

  • Click + at the lower left of the chat, or type /.
  • Hover Connectors.
  • Turn on Composio.
  • Ask Claude to connect to Mailtrap again.

2. Why does Claude show an MCP server error before Mailtrap connects?

Claude can show Couldn't reach the MCP server or Authorization with the MCP server failed when you add the connector for Mailtrap.

  • Check that the connector URL is https://connect.composio.dev/mcp.
  • Connectors run from Anthropic's cloud, so your device network is usually not the problem.
  • Add the connector again from Customize > Connectors, then ask Claude to connect Mailtrap.
  • If it fails again, send the error and the ofid_ reference id to support@composio.dev.

3. Why does the Mailtrap authorization link not work?

The Composio connector is one server. Your Mailtrap account connects separately when Claude asks for it.

  • If the browser does not open, or the link expires, ask Claude to retry the Mailtrap connection.
  • Composio creates a fresh Mailtrap authorization link.
  • Open that link in your browser and finish the Mailtrap sign-in.

4. Why do Mailtrap actions fail after they worked before?

The Mailtrap connection can expire or lose permission.

  • Ask Claude to inspect the Mailtrap connection.
  • If the connection is unhealthy, disconnect it when Claude prompts you.
  • Reconnect the Mailtrap account and retry the action.
  • If Claude shows a permission prompt, approve it before Claude changes data in Mailtrap.
  • If the action still fails with a permission error, check that the connected account has that permission in Mailtrap itself.

5. How do I switch to a different Mailtrap account?

Claude can manage the Mailtrap connection for you.

  • Ask Claude to disconnect or delete the current Mailtrap account.
  • Ask Claude to connect Mailtrap again.
  • Open the new Composio authorization link for Mailtrap.
  • Sign in with the other Mailtrap account in the browser.
  • After the account connects, ask Claude to retry the Mailtrap task.

6. Why is my Mailtrap connection missing in Claude Desktop or on a Team plan?

The connector belongs to your Claude account, so your Mailtrap connection works in Claude Web, Desktop, and Cowork.

  • In Claude Desktop, open Customize > Connectors.
  • Next to Composio, click ⋮ and click Clear cache.
  • If Mailtrap tools still do not appear, click ⋮, disconnect, remove the connector, and add it again.
  • On Team or Enterprise, an Owner or Primary Owner must enable the connector before you can connect Mailtrap.
TOOLS

Supported Tools

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

Clean Inbox

Tool to clean an inbox in Mailtrap by deleting all messages.

Create Contact

Tool to create a new contact in Mailtrap.

Create Contact Event

Tool to create a contact event in Mailtrap.

Create Contact Export

Tool to create a contact export job for a Mailtrap account.

Create Contact Field

Tool to create a custom contact field in Mailtrap.

Create Contact List

Tool to create a new contact list in Mailtrap.

Create Email Template

Tool to create a new email template in Mailtrap account.

Create Sending Domain

Tool to create a new sending domain in Mailtrap.

Delete Contact

Tool to delete a contact from a Mailtrap account.

Delete Contact Field

Tool to delete a contact field by its ID.

Delete Contact List

Tool to delete a contact list by its ID.

Delete Email Template

Tool to delete an email template from a Mailtrap account.

Delete Project

Tool to delete a project from Mailtrap.

Delete Sending Domain

Tool to delete a sending domain from a Mailtrap account.

Get Billing Usage

Tool to retrieve current billing cycle usage for an account.

Get Contact

Tool to retrieve a contact by UUID or email address from Mailtrap.

Get Contact Export

Tool to retrieve the status of a contact export.

Get Contact Field

Tool to retrieve contact field details by field ID.

Get Contact Import Status

Tool to retrieve the status of a contact import operation.

Get Contact List

Tool to retrieve a specific contact list by its ID.

Get Email Template

Tool to retrieve details of a specific email template by ID.

Get Inbox Attributes

Tool to retrieve inbox attributes from Mailtrap.

Get Message HTML Body

Tool to retrieve the HTML body of a message from Mailtrap.

Get Permission Resources

Tool to retrieve all resources in account for permission management.

Get Project by ID

Tool to retrieve project details from Mailtrap by project ID.

Get Sending Domain

Tool to retrieve sending domain details from Mailtrap.

Get Sending Stats

Tool to retrieve email sending statistics from Mailtrap for a specific account.

Get Sending Stats by Categories

Tool to retrieve email sending statistics grouped by categories.

Get Sending Stats by Date

Tool to retrieve email sending statistics aggregated by date.

Get Sending Stats by Domains

Tool to retrieve sending statistics grouped by domains for a Mailtrap account.

Get Sending Stats by ESP

Tool to retrieve email sending statistics grouped by email service providers (ESPs) for a specified date range.

Import Contacts

Tool to import contacts in bulk to Mailtrap.

List Accounts

Tool to list all Mailtrap accounts you have access to.

List Contact Fields

Tool to get all contact fields for a Mailtrap account.

List Contact Lists

Tool to retrieve all contact lists for a Mailtrap account.

List Email Templates

Tool to retrieve all email templates for a Mailtrap account.

List Inboxes

Tool to get a list of inboxes for a Mailtrap account.

List Messages in Inbox

Tool to get messages from a Mailtrap inbox.

List Projects

Tool to get a list of projects for a Mailtrap account.

List Sending Domains

Tool to list all sending domains for a Mailtrap account.

List Email Suppressions

Tool to list suppressed email addresses for a Mailtrap account.

Mark Inbox as Read

Tool to mark all messages in a Mailtrap inbox as read.

Reset Inbox Credentials

Tool to reset SMTP credentials for a Mailtrap inbox.

Update contact

Tool to update an existing contact in Mailtrap.

Update Contact Field

Tool to update a contact field in Mailtrap.

Update Contact List

Tool to update a contact list's name in Mailtrap.

Update Email Template

Tool to update an existing email template in Mailtrap account.

Update inbox

Tool to update an inbox's settings in Mailtrap.

Update project

Tool to update a project's name in Mailtrap.

FRAMEWORKS

How to build Mailtrap MCP Agent with another framework

Claude Code logo

Claude Code

Use Mailtrap MCP with Claude Code

Cursor logo

Cursor

Use Mailtrap MCP with Cursor

ChatGPT logo

ChatGPT

Use Mailtrap MCP with ChatGPT

Antigravity logo

Antigravity

Use Mailtrap MCP with Antigravity

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Mailtrap MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Mailtrap MCP with Claude Agent SDK

Codex logo

Codex

Use Mailtrap MCP with Codex

Grok Build logo

Grok Build

Use Mailtrap MCP with Grok Build

VS Code logo

VS Code

Use Mailtrap MCP with VS Code

OpenCode logo

OpenCode

Use Mailtrap MCP with OpenCode

OpenClaw logo

OpenClaw

Use Mailtrap MCP with OpenClaw

Hermes logo

Hermes

Use Mailtrap MCP with Hermes

Atomic Agent logo

Atomic Agent

Use Mailtrap MCP with Atomic Agent

Google ADK logo

Google ADK

Use Mailtrap MCP with Google ADK

LangChain logo

LangChain

Use Mailtrap MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Mailtrap MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Mailtrap MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Mailtrap MCP with LlamaIndex

CrewAI logo

CrewAI

Use Mailtrap MCP with CrewAI

Pydantic AI logo

Pydantic AI

Use Mailtrap MCP with Pydantic AI

AutoGen logo

AutoGen

Use Mailtrap MCP with AutoGen

FAQ

Frequently asked questions

With a standalone Mailtrap MCP server, the agents and LLMs can only access a fixed set of Mailtrap tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Mailtrap and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Claude Cowork fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Mailtrap tools.

Yes, absolutely. You can configure which Mailtrap scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Mailtrap data and credentials are handled as safely as possible.

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