Add the Postmark MCP server to Claude Desktop

Config last verified Jun 1, 2026

The exact config to run Postmark in Claude Desktop — paste it in, restart, and the tools load.

Prerequisites

Claude Desktop installed.
POSTMARK_SERVER_TOKEN — Your Postmark server API token.
DEFAULT_SENDER_EMAIL — Default verified sender email address.
DEFAULT_MESSAGE_STREAM — Postmark message stream to send through (e.g., 'outbound').

Setup

1. Open `~/Library/Application Support/Claude/claude_desktop_config.json`

On Windows the file lives at %APPDATA%\Claude\claude_desktop_config.json.

2. Add this configuration

Add to ~/Library/Application Support/Claude/claude_desktop_config.json

~/Library/Application Support/Claude/claude_desktop_config.json

json

{
  "mcpServers": {
    "postmark": {
      "command": "node",
      "args": [
        "/path/to/postmark-mcp/index.js"
      ],
      "env": {
        "POSTMARK_SERVER_TOKEN": "<POSTMARK_SERVER_TOKEN>",
        "DEFAULT_SENDER_EMAIL": "<DEFAULT_SENDER_EMAIL>",
        "DEFAULT_MESSAGE_STREAM": "<DEFAULT_MESSAGE_STREAM>"
      }
    }
  }
}

3. Restart Claude Desktop and confirm the Postmark tools load.

Gotchas

Claude Desktop reads MCP servers from an "mcpServers" object, but the config file is stdio-only: it cannot dial a remote URL directly. To reach a remote server you bridge it locally by running "npx mcp-remote <url>" as the command. Native remote Connectors exist on paid plans, but not through this config file, so the bridge is the portable path.

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