How to integrate Mailtrap MCP with ChatGPT

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How to integrate Mailtrap MCP with ChatGPT

ChatGPT is one of the most popular AI tools today, with capabilities ranging from deep research and image generation to writing, coding, and everyday productivity.

In this guide, I will explain the easiest and most secure way to connect your Mailtrap account to ChatGPT via Composio Connect, so it can summarize unread updates from this morning, create draft replies to urgent messages, fetch contact details for recent senders, and more without ever putting your account credentials at risk.

Also integrate Mailtrap with

Why use Composio over default connectors?

  • Apps with read and write access. Default connectors mostly can read your data. Composio's Mailtrap integration lets ChatGPT take actions like creating drafts, sending updates, labeling records, and more.
  • 1,000+ SaaS toolkits out of the box. Composio gives you instant access to a vast catalog of pre-built connectors, from Gmail and Slack to Notion, Linear, and Salesforce.
  • One MCP server for every app. Connect any of your applications on demand through a single endpoint, rather than juggling a separate server for each app.
  • Smart, context-aware tool loading. Unlike traditional MCP servers that dump every available tool into the LLM context window, Composio searches for and loads only the tools relevant to the task at hand.
  • Cross-app automation. Chain actions across multiple apps in a single run - fetch a thread, summarize it in Notion, and post highlights to Slack without leaving the conversation.

Prerequisites

  • A ChatGPT account with Plus subscription or higher (Business, Enterprise, Edu, or Pro). We will use ChatGPT Web.
  • Access to the Mailtrap workspace you want to connect.
  • Composio MCP.

Note: Composio connects through OAuth. You will be asked to sign in and approve specific permissions. Review the permission screen carefully if you are using a work account.

Step-by-step: Connect Mailtrap to ChatGPT

1. Enable Developer Mode

In ChatGPT, go to Settings > Apps > Advanced settings and turn on Developer Mode.

ChatGPT settings showing Developer Mode toggle

2. Add the MCP server

Click Create app, then paste the Composio MCP server URL:

bash
https://connect.composio.dev/mcp
ChatGPT create app flow with Composio MCP URL

3. Authorize in your browser

A browser window will open automatically. Sign in to authorize ChatGPT to access your Composio account.

Composio authorization screen for ChatGPT MCP setup

4. Start using Composio

Composio tools are now available in ChatGPT chats and Deep Research. In every new chat, click the + icon at the bottom, click More, and select Composio to enable tools for that conversation.

What you can do after connecting Mailtrap

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

Security + privacy notes (important)

  • Use least-privilege access: Only grant permissions you actually need.
  • Review OAuth permissions before approving: Make sure requested scopes match what you expect Composio and ChatGPT to do.
  • Keep write actions human-reviewed: For actions like sending messages, creating labels, or editing drafts, keep manual confirmation enabled.
  • Be careful with sensitive data: Avoid using this setup with highly sensitive information unless allowed by your personal, company, or client policies.

Supported Tools & Triggers

Tools
Clean InboxTool to clean an inbox in Mailtrap by deleting all messages.
Create ContactTool to create a new contact in Mailtrap.
Create Contact EventTool to create a contact event in Mailtrap.
Create Contact ExportTool to create a contact export job for a Mailtrap account.
Create Contact FieldTool to create a custom contact field in Mailtrap.
Create Contact ListTool to create a new contact list in Mailtrap.
Create Email TemplateTool to create a new email template in Mailtrap account.
Create Sending DomainTool to create a new sending domain in Mailtrap.
Delete ContactTool to delete a contact from a Mailtrap account.
Delete Contact FieldTool to delete a contact field by its ID.
Delete Contact ListTool to delete a contact list by its ID.
Delete Email TemplateTool to delete an email template from a Mailtrap account.
Delete ProjectTool to delete a project from Mailtrap.
Delete Sending DomainTool to delete a sending domain from a Mailtrap account.
Get Billing UsageTool to retrieve current billing cycle usage for an account.
Get ContactTool to retrieve a contact by UUID or email address from Mailtrap.
Get Contact ExportTool to retrieve the status of a contact export.
Get Contact FieldTool to retrieve contact field details by field ID.
Get Contact Import StatusTool to retrieve the status of a contact import operation.
Get Contact ListTool to retrieve a specific contact list by its ID.
Get Email TemplateTool to retrieve details of a specific email template by ID.
Get Inbox AttributesTool to retrieve inbox attributes from Mailtrap.
Get Message HTML BodyTool to retrieve the HTML body of a message from Mailtrap.
Get Permission ResourcesTool to retrieve all resources in account for permission management.
Get Project by IDTool to retrieve project details from Mailtrap by project ID.
Get Sending DomainTool to retrieve sending domain details from Mailtrap.
Get Sending StatsTool to retrieve email sending statistics from Mailtrap for a specific account.
Get Sending Stats by CategoriesTool to retrieve email sending statistics grouped by categories.
Get Sending Stats by DateTool to retrieve email sending statistics aggregated by date.
Get Sending Stats by DomainsTool to retrieve sending statistics grouped by domains for a Mailtrap account.
Get Sending Stats by ESPTool to retrieve email sending statistics grouped by email service providers (ESPs) for a specified date range.
Import ContactsTool to import contacts in bulk to Mailtrap.
List AccountsTool to list all Mailtrap accounts you have access to.
List Contact FieldsTool to get all contact fields for a Mailtrap account.
List Contact ListsTool to retrieve all contact lists for a Mailtrap account.
List Email TemplatesTool to retrieve all email templates for a Mailtrap account.
List InboxesTool to get a list of inboxes for a Mailtrap account.
List Messages in InboxTool to get messages from a Mailtrap inbox.
List ProjectsTool to get a list of projects for a Mailtrap account.
List Sending DomainsTool to list all sending domains for a Mailtrap account.
List Email SuppressionsTool to list suppressed email addresses for a Mailtrap account.
Mark Inbox as ReadTool to mark all messages in a Mailtrap inbox as read.
Reset Inbox CredentialsTool to reset SMTP credentials for a Mailtrap inbox.
Update contactTool to update an existing contact in Mailtrap.
Update Contact FieldTool to update a contact field in Mailtrap.
Update Contact ListTool to update a contact list's name in Mailtrap.
Update Email TemplateTool to update an existing email template in Mailtrap account.
Update inboxTool to update an inbox's settings in Mailtrap.
Update projectTool to update a project's name in Mailtrap.

How to build Mailtrap MCP Agent with another framework

FAQ

What are the differences in Tool Router MCP and Mailtrap MCP?

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.

Can I use Tool Router MCP with ChatGPT?

Yes, you can. ChatGPT 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.

Can I manage the permissions and scopes for Mailtrap while using Tool Router?

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.

How safe is my data with Composio Tool Router?

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.

Used by agents from

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HubSpot
Agent.ai
Altera
DataStax
Entelligence
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Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

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