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Smtp

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A Model Context Protocol server for SMTP email services

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A Model Context Protocol server for SMTP email services

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One MCP server connecting multiple email accounts

Email SMTP/IMAP MCP

One local MCP server for every inbox: search, read, send, reply, forward, and organize email across multiple accounts.

release npm downloads CI Node.js stars license

Why this server

  • No account-count cap — add work, personal, support, or client inboxes and switch with account_name.
  • SMTP + IMAP together — send and receive through one small MCP server.
  • Complete everyday workflow — search, read, reply, forward, attach files, flag, archive, move, and list folders.
  • Provider-agnostic — works with Gmail, iCloud Mail, Fastmail, Outlook, self-hosted mail, and other standard SMTP/IMAP providers.
  • Local stdio transport — no hosted relay and no separate control panel.

Search, send, respond, organize, and browse folders across accounts

Quick start

1. Create your .env

Copy .env.example to a private location and add as many named accounts as you need:

EMAIL_ACCOUNTS_JSON='{
  "work": {
    "smtp": {
      "host": "smtp.gmail.com",
      "port": 587,
      "secure": false,
      "user": "[email protected]",
      "password": "app-password"
    },
    "imap": {
      "host": "imap.gmail.com",
      "port": 993,
      "secure": true,
      "user": "[email protected]",
      "password": "app-password"
    },
    "default_from_name": "Your Name",
    "sender_emails": ["[email protected]", "[email protected]"]
  },
  "personal": {
    "smtp": {
      "host": "smtp.mail.me.com",
      "port": 587,
      "secure": false,
      "user": "[email protected]",
      "password": "app-password"
    },
    "imap": {
      "host": "imap.mail.me.com",
      "port": 993,
      "secure": true,
      "user": "[email protected]",
      "password": "app-password"
    }
  }
}'

DEFAULT_EMAIL_ACCOUNT="work"

The server loads .env from its working directory automatically. EMAIL_ENV_FILE lets an MCP client use an .env stored anywhere.

2. Add the MCP server

For Claude Desktop, edit:

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
  • Windows: %APPDATA%\Claude\claude_desktop_config.json
{
  "mcpServers": {
    "email": {
      "command": "npx",
      "args": ["-y", "email-smtp-imap-mcp"],
      "env": {
        "EMAIL_ENV_FILE": "/absolute/path/to/your/.env"
      }
    }
  }
}

Use an absolute path, restart your MCP client, then ask: “List my configured email accounts.”

Pass account JSON directly from the MCP client

You can skip the .env file and set EMAIL_ACCOUNTS_JSON plus DEFAULT_EMAIL_ACCOUNT directly in the MCP client’s env object. The JSON must be escaped into a single string.

{
  "env": {
    "EMAIL_ACCOUNTS_JSON": "{\"work\":{\"smtp\":{\"host\":\"smtp.gmail.com\",\"port\":587,\"user\":\"[email protected]\",\"password\":\"app-password\"},\"imap\":{\"host\":\"imap.gmail.com\",\"port\":993,\"user\":\"[email protected]\",\"password\":\"app-password\"}}}",
    "DEFAULT_EMAIL_ACCOUNT": "work"
  }
}
Single-account `.env` variables

Use SMTP_HOST, SMTP_PORT, SMTP_SECURE, SMTP_USER, SMTP_PASS, IMAP_HOST, IMAP_PORT, IMAP_SECURE, IMAP_USER, and IMAP_PASS instead of EMAIL_ACCOUNTS_JSON.

SMTP_USERNAME/SMTP_PASSWORD and IMAP_USERNAME/IMAP_PASSWORD are accepted aliases. IMAP credentials default to the SMTP credentials when omitted. Use SENDER_EMAILS as a comma-separated allowlist for optional from_email selection.

Tools

Tool What it does
accounts_list List every configured account and identify the default without exposing credentials.
emails_find Search by text, sender, recipient, subject, date, read state, flag state, or attachments. Optionally return bodies and attachments.
email_send Send plain-text or HTML email with CC, BCC, sender aliases, and base64 attachments.
email_respond Reply, reply-all, or forward by email UID with threading and optional original attachments.
emails_modify Mark read/unread, flag/unflag, or move messages to another folder.
folders_list List folders with optional total and unread counts.

Every email tool accepts an optional account_name. Without it, the server uses DEFAULT_EMAIL_ACCOUNT or the first configured account. There is no application-level account-count limit.

Verify your setup

After restarting the MCP client, try these in order:

  1. “List my configured email accounts.”
  2. “List folders for my work account.”
  3. “Find the five newest unread emails in my personal account.”
  4. “Send a plain-text email from my work account.”

Provider settings

Provider SMTP IMAP Credential
Gmail smtp.gmail.com:587 imap.gmail.com:993 App password
iCloud Mail smtp.mail.me.com:587 imap.mail.me.com:993 App-specific password
Other providers Use the provider's SMTP host Use the provider's IMAP host Provider password or app password

Use secure: true for implicit TLS ports such as 465/993. Port 587 normally uses secure: false and upgrades with STARTTLS.

Development

git clone https://github.com/samihalawa/email-smtp-imap-mcp.git
cd email-smtp-imap-mcp
npm ci
npm test

Run the compiled stdio server with npm start. Build a production container with docker build -t email-smtp-imap-mcp ..

Contributing

Issues and focused pull requests are welcome. See CONTRIBUTING.md for the development workflow and SECURITY.md for vulnerability reports.

License

MIT © Sami Halawa

from github.com/samihalawa/mcp-server-smtp

Install Smtp in Claude Desktop, Claude Code & Cursor

Recommended · one command, every IDE
unyly install smtp

Installs into Claude Desktop, Claude Code, Cursor & VS Code — handles npx, uvx and build-from-source repos for you.

First time? Get the CLI: curl -fsSL https://unyly.org/install | sh

Or configure manually

Run in your terminal:

claude mcp add smtp -- npx -y github:samihalawa/mcp-server-smtp

Step-by-step: how to install Smtp

FAQ

Is Smtp MCP free?

Yes, Smtp MCP is free — one-click install via Unyly at no cost.

Does Smtp need an API key?

No, Smtp runs without API keys or environment variables.

Is Smtp hosted or self-hosted?

Self-hosted: the server runs locally on your machine via the install command above.

How do I install Smtp in Claude Desktop, Claude Code or Cursor?

Open Smtp on unyly.org, pick your client tab (Claude Desktop, Claude Code, Cursor) and press Install — the config is generated automatically, no JSON editing.

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