Postmark MCP Server

The Postmark MCP server is an official, experimental Model Context Protocol implementation from Postmark Labs (ActiveCampaign) that lets AI assistants send transactional and template-based emails through a Postmark account. It wraps the core Postmark email API with a small, focused set of MCP tools so agents can dispatch one-off messages, render templates, and review delivery performance without writing custom integration code.

The server is a Node.js process (v16+) that authenticates with a Postmark server token and reads a default sender address and message stream from environment variables. Every outbound email automatically enables open tracking and link tracking, and the server includes structured error handling, secure logging, and a graceful shutdown path. It is designed to be run locally and registered with MCP clients like Claude Desktop and Cursor via a standard mcpServers configuration block.

Tool coverage is intentionally narrow: sendEmail, sendEmailWithTemplate, listTemplates, and getDeliveryStats. That makes it a good fit for agent workflows that need to deliver notifications, follow-ups, or campaign emails, but it is not a full Postmark API client (no bounce management, suppression list editing, or server administration).

Tools

Prerequisites

• Node.js v16 or higher
• A Postmark account with a server API token
• A verified sender signature or domain in Postmark

Install

git clone https://github.com/ActiveCampaign/postmark-mcp
cd postmark-mcp
npm install

Configure environment

Copy the example env file and fill in your credentials:

cp .env.example .env

Required environment variables:

• POSTMARK_SERVER_TOKEN: your Postmark server API token
• DEFAULT_SENDER_EMAIL: a verified "from" address
• DEFAULT_MESSAGE_STREAM: typically outbound for transactional mail or broadcast for broadcasts

MCP client config

Add the server to your MCP client (Claude Desktop, Cursor, etc.):

{
  "mcpServers": {
    "postmark": {
      "command": "node",
      "args": ["path/to/postmark-mcp/index.js"],
      "env": {
        "POSTMARK_SERVER_TOKEN": "your-token",
        "DEFAULT_SENDER_EMAIL": "sender@example.com",
        "DEFAULT_MESSAGE_STREAM": "outbound"
      }
    }
  }
}

Restart your MCP client and the postmark server should appear with its four tools available.

• Have an agent draft and send transactional notifications (order confirmations, password resets, internal alerts) directly through Postmark without writing API code.
• Trigger templated lifecycle emails (welcome, onboarding, renewal reminders) by passing a templateAlias and a templateModel of variables.
• Audit available templates in a Postmark server before launching a campaign so the agent picks the correct one.
• Pull delivery stats by date range or tag to answer questions like "how did the q2-renewal campaign perform last week?"
• Wire Postmark into broader agent workflows, for example: detect a churn signal in CRM data, then send a templated win-back email and log the result.

• "Send a plain-text email to alex@example.com with subject 'Welcome' and a short onboarding message."
• "Send the password-reset template to jane@example.com with templateModel {reset_url: 'https://app.example.com/r/abc'}."
• "List all email templates available in our Postmark server."
• "Show delivery stats for the newsletter tag between 2026-04-01 and 2026-04-30."
• "Send a follow-up email to the lead I just researched and tag it sales-followup."

• Official implementation from Postmark Labs (ActiveCampaign), MIT licensed.
• Small, well-scoped tool surface that maps cleanly to common transactional email tasks.
• Open and link tracking are enabled by default, and delivery stats are exposed as a first-class tool.
• Simple Node.js setup with explicit Claude Desktop and Cursor configuration in the README.

• Marked "experimental" by the maintainers; not all Postmark API surface is exposed (no bounce, suppression, server, or webhook management).
• Limited to four tools, so use cases like inbound parsing, message search, or attachments may require direct API calls.
• Requires self-hosting the Node process and managing a Postmark server token locally; no provider-hosted remote MCP endpoint.

• Resend MCP: official Resend server for sending emails from an MCP client.
• SendGrid community MCP servers: various community implementations wrapping the SendGrid API.
• Direct use of the Postmark REST API via a generic HTTP/Fetch MCP server if you need endpoints this server does not cover.