MailPace MCP (Model Context Protocol) Server

MailPace MCP Server exposes the MailPace transactional email, domain management, and email status APIs to MCP clients.

Features

• Send transactional email with the Send API
• List, create, update, and verify domains with the Domains API
• Manage domain API tokens
• Check delivery, bounce, and deferral status with the Email Status API
• Optional recipient allowlist and idempotent sends
• Tools expose structured output schemas and MCP behavior annotations

Requirements

• Node.js 20 or newer
• A MailPace organization and domain
• A domain API token to send email and check email status for that domain
• An organization API token to manage domains and domain API tokens

Configuration

Credentials are read from environment variables only. They are never accepted as command-line arguments, which would expose them in process listings.

Variable	Required	Description
MAILPACE_API_TOKEN	For sending and domain-scoped status	Domain API token
MAILPACE_ORGANIZATION_TOKEN	For domain management	Organization API token
MAILPACE_ALLOWED_RECIPIENTS	No	Comma-separated allowlist of exact addresses or @domain rules. When set, mailpace_send_email refuses other recipients.
MAILPACE_API_URL	No	Override the API base URL. Must be HTTPS except for localhost development.
MAILPACE_REQUEST_TIMEOUT_MS	No	Per-request timeout in milliseconds. Default 30000.
MAILPACE_MAX_RETRIES	No	Retries for idempotent requests and 429 responses. Default 2.

At least one of MAILPACE_API_TOKEN or MAILPACE_ORGANIZATION_TOKEN is required. Tools are registered according to the available credentials.

Tools

Tool	Credential	Description
mailpace_send_email	Domain token	Send an email. Supports attachments, tags, and Idempotency-Key.
mailpace_get_email_status	Domain or organization token	Get delivery, bounce, or deferral status by domain and email ID.
mailpace_list_domains	Organization token	List domains with pagination and sorting.
mailpace_get_domain	Organization token	Get a domain by ID.
mailpace_create_domain	Organization token	Create a sending domain.
mailpace_update_domain	Organization token	Update a domain's name or URL.
mailpace_verify_domain	Organization token	Check DKIM and advanced verification DNS records.
mailpace_list_domain_api_tokens	Organization token	List a domain's API tokens.
mailpace_get_domain_api_token	Organization token	Get one domain API token.
mailpace_create_domain_api_token	Organization token	Create a domain API token. Store the returned token securely.
mailpace_update_domain_api_token	Organization token	Rename a domain API token.
mailpace_revoke_domain_api_token	Organization token	Revoke a domain API token. This cannot be undone.

Sending email safely

mailpace_send_email is an external side effect. Clients and hosts should confirm recipients before invoking it. For automation, set MAILPACE_ALLOWED_RECIPIENTS to reduce the impact of mistakes or prompt injection, for example:

MAILPACE_ALLOWED_RECIPIENTS="hello@example.com,@yourcompany.com"

Use an idempotency_key when retrying a send to prevent duplicate email delivery.

Client configuration

After building locally, point your MCP client at the built entry point:

{
  "mcpServers": {
    "mailpace": {
      "command": "node",
      "args": ["/absolute/path/to/mailpace-mcp/build/index.js"],
      "env": {
        "MAILPACE_API_TOKEN": "your-domain-api-token",
        "MAILPACE_ORGANIZATION_TOKEN": "your-organization-api-token"
      }
    }
  }
}

Once published, this can also be run with `npx

... View full README on GitHub