Email Sending MCP
A simple MCP server that enables users to send emails using Resend's API, integrating with tools like Cursor and Claude Desktop for seamless email composition and delivery.
README Documentation
Resend MCP Server
An MCP server for the Resend platform. Send and receive emails, manage contacts, broadcasts, domains, and more — directly from any MCP client like Claude Desktop, Cursor, or Claude Code.
Features
- Emails — Send, list, get, cancel, update, and batch send emails. Supports HTML, plain text, attachments (local file, URL, or base64), CC/BCC, reply-to, scheduling, tags, and topic-based sending.
- Received Emails — List and read inbound emails. List and download received email attachments.
- Contacts — Create, list, get, update, and remove contacts. Manage segment memberships and topic subscriptions. Supports custom contact properties.
- Broadcasts — Create, send, list, get, update, and remove broadcast campaigns. Supports scheduling, personalization placeholders, and preview text.
- Domains — Create, list, get, update, remove, and verify sender domains. Configure tracking, TLS, and sending/receiving capabilities.
- Segments — Create, list, get, and remove audience segments.
- Topics — Create, list, get, update, and remove subscription topics.
- Contact Properties — Create, list, get, update, and remove custom contact attributes.
- API Keys — Create, list, and remove API keys.
- Webhooks — Create, list, get, update, and remove webhooks for event notifications.
Setup
Create a free Resend account and create an API key. To send to addresses outside of your own, you'll need to verify your domain.
Usage
The server supports two transport modes: stdio (default) and HTTP.
Stdio Transport (Default)
Claude Code
claude mcp add resend -e RESEND_API_KEY=re_xxxxxxxxx -- npx -y resend-mcp
Cursor
Open the command palette and choose "Cursor Settings" > "MCP" > "Add new global MCP server".
{
"mcpServers": {
"resend": {
"command": "npx",
"args": ["-y", "resend-mcp"],
"env": {
"RESEND_API_KEY": "re_xxxxxxxxx"
}
}
}
}
Claude Desktop
Open Claude Desktop settings > "Developer" tab > "Edit Config".
{
"mcpServers": {
"resend": {
"command": "npx",
"args": ["-y", "resend-mcp"],
"env": {
"RESEND_API_KEY": "re_xxxxxxxxx"
}
}
}
}
HTTP Transport
Run the server over HTTP for remote or web-based integrations. In HTTP mode, each client authenticates by passing their Resend API key as a Bearer token in the Authorization header.
Start the server:
npx -y resend-mcp --http --port 3000
The server will listen on http://127.0.0.1:3000 and expose the MCP endpoint at /mcp using Streamable HTTP.
Claude Code
claude mcp add resend --transport http http://127.0.0.1:3000/mcp --header "Authorization: Bearer re_xxxxxxxxx"
Cursor
Open the command palette and choose "Cursor Settings" > "MCP" > "Add new global MCP server".
{
"mcpServers": {
"resend": {
"url": "http://127.0.0.1:3000/mcp",
"headers": {
"Authorization": "Bearer re_xxxxxxxxx"
}
}
}
}
You can also set the port via the MCP_PORT environment variable:
MCP_PORT=3000 npx -y resend-mcp --http
Options
You can pass additional arguments to configure the server:
--key: Your Resend API key (stdio mode only; HTTP mode uses the Bearer token from the client)--sender: Default sender email address from a verified domain--reply-to: Default reply-to email address (can be specified multiple times)--http: Use HTTP transport instead of stdio (default: stdio)--port: HTTP port when using--http(default: 3000, orMCP_PORTenv var)
Environment variables:
RESEND_API_KEY: Your Resend API key (required for stdio, optional for HTTP since clients pass it via Bearer token)SENDER_EMAIL_ADDRESS: Default sender email address from a verified domain (optional)REPLY_TO_EMAIL_ADDRESSES: Comma-separated reply-to email addresses (optional)MCP_PORT: HTTP port when using--http(optional)
[!NOTE] If you don't provide a sender email address, the MCP server will ask you to provide one each time you call the tool.
Local Development
- Clone this project and build:
git clone https://github.com/resend/resend-mcp.git
pnpm install
pnpm run build
- To use the local build, replace the
npxcommand with the path to your local build:
Claude Code (stdio):
claude mcp add resend -e RESEND_API_KEY=re_xxxxxxxxx -- node ABSOLUTE_PATH_TO_PROJECT/dist/index.js
Claude Code (HTTP):
claude mcp add resend --transport http http://127.0.0.1:3000/mcp --header "Authorization: Bearer re_xxxxxxxxx"
Cursor / Claude Desktop (stdio):
{
"mcpServers": {
"resend": {
"command": "node",
"args": ["ABSOLUTE_PATH_TO_PROJECT/dist/index.js"],
"env": {
"RESEND_API_KEY": "re_xxxxxxxxx"
}
}
}
}
Cursor (HTTP):
{
"mcpServers": {
"resend": {
"url": "http://127.0.0.1:3000/mcp",
"headers": {
"Authorization": "Bearer re_xxxxxxxxx"
}
}
}
}
Testing with MCP Inspector
Note: Make sure you've built the project first (see Local Development section above).
Using Stdio Transport
-
Set your API key:
export RESEND_API_KEY=re_your_key_here -
Start the inspector:
pnpm inspector -
In the browser (Inspector UI):
- Choose stdio (launch a process).
- Command:
node - Args:
dist/index.js(or the full path todist/index.js) - Env:
RESEND_API_KEY=re_your_key_here(or leave blank if you already exported it in the same terminal). - Click Connect, then use "List tools" to verify the server is working.
Using HTTP Transport
-
Start the HTTP server in one terminal:
node dist/index.js --http --port 3000 -
Start the inspector in another terminal:
pnpm inspector -
In the browser (Inspector UI):
- Choose Streamable HTTP (connect to URL).
- URL:
http://127.0.0.1:3000/mcp - Add a custom header:
Authorization: Bearer re_your_key_hereand activate the toggle. - Click Connect, then use "List tools" to verify the server is working.