How to integrate Mailersend MCP with Atomic Agent

Atomic Agent is an open-source AI agent that runs on your machine and supports local models through llama.cpp. Connect it to 1,500+ apps through Composio, including Mailersend.

This guide uses Atomic Agent's built-in Composio integration. You need Atomic Agent v0.5.6 or later, your own Composio API key, and a Mailersend account. See the Atomic Agent documentation for installation instructions.

How Atomic Agent connects to Mailersend

Atomic Agent connects to Composio's Tool Router over Streamable HTTP MCP. It discovers the tools needed for your request, and Composio handles account authentication.

Execution and account-connection tools follow Atomic Agent's configured approval policy. Review any approval prompt before allowing an action on your connected account.

Connect Mailersend to Atomic Agent

1. Sign up or sign in to the Composio dashboard. Copy your API key.
2. In Atomic Agent, open the Integrations tab and select Composio. Select API key, press e, paste the key, and press Enter. The tools become available immediately, without a restart.
3. Ask Atomic Agent to do something in Mailersend. It searches Composio for the right tool.
4. On first use, open the sign-in link returned in the chat. Connect your Mailersend account, then return to Atomic Agent to continue.

Headless setup

Add the following line to ~/.atomic-agent/.env, replacing YOUR_COMPOSIO_API_KEY with your key. Start Atomic Agent after saving the file.

The Mailersend MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Mailersend account. It provides structured and secure access to your transactional email infrastructure, so your agent can perform actions like sending emails, managing domains, configuring webhooks, and monitoring API usage on your behalf.

• Seamless domain management: Register new sending domains, verify their status, and retrieve detailed configuration information to ensure reliable email delivery.
• Automated email and SMTP user setup: Quickly create SMTP users and API tokens as needed for secure and scalable application integration.
• Webhook configuration and event tracking: Set up and delete webhooks to monitor real-time email events such as sent, delivered, or opened messages, enabling proactive workflows and notifications.
• Recipient and quota insights: List recipients for specific domains and monitor your API usage to stay within account limits and optimize deliverability.
• Centralized resource discovery: Retrieve general API resources and overview endpoints to streamline Mailersend integration and administration directly from your agent.

Use Mailersend from Atomic Agent

With your account connected, ask Atomic Agent to work with Mailersend in natural language. You can connect more apps through the same Composio integration as you need them.

Visit the Atomic Agent website or inspect the Atomic Agent source code.