Noise-watch-apps

gmail-multi: an MCP server for sending from two Gmail accounts

A small MCP server that sends email through the Gmail API from more than one Google account, such as work and personal. You pick the sender on each call. The default is personal, so the weekly Wrist Log health report goes to your personal inbox unless you say otherwise.

It has two tools:

Tool What it does
list_accounts Shows the configured senders, the default one, whether each is signed in, and any recipient allowlist.
send_email to, subject, body, plus optional account, html, cc and bcc.

It asks for only the gmail.send permission. The server can send mail, but it can’t read, search or delete anything in either mailbox.

Step 1: Create a Google Cloud project and turn on the Gmail API

  1. Go to https://console.cloud.google.com/ and sign in with your personal account.
  2. Create a project, for example wrist-log-mailer.
  3. Go to APIs & Services → Library, search for Gmail API and click Enable.
  1. Go to APIs & Services → OAuth consent screen (also called Google Auth Platform → Branding / Audience).
  2. For User type, choose External. This lets both a @gmail.com account and a work account sign in.
  3. Fill in an app name and your email address. You can skip the logo and domains.
  4. Under Data access / Scopes, add https://www.googleapis.com/auth/gmail.send.
  5. Under Audience, add both your personal and work addresses as test users.

About the 7-day limit. When an External app is in Testing status, its refresh tokens expire after 7 days. Your Sunday report would then start failing a week after you sign in. Once everything works, go to Audience and click Publish app to move it to In production. You don’t need Google’s verification for your own use. You’ll see an “unverified app” warning when you sign in. Click Advanced → Go to … (unsafe) to continue. It’s your app, so this is safe.

Step 3: Create a Desktop OAuth client

  1. Go to APIs & Services → Credentials → Create credentials → OAuth client ID.
  2. For Application type, choose Desktop app.
  3. Download the JSON file, rename it to client_secret.json and put it in this folder. Git ignores it, so it won’t be committed.

Step 4: Install

cd gmail-mcp
python3 -m venv .venv
.venv/bin/pip install -r requirements.txt

This needs Python 3.10 or later. On Windows, use .venv\Scripts\pip and .venv\Scripts\python instead.

Step 5: Describe your two accounts

cp accounts.example.json accounts.json

Edit accounts.json:

{
  "default_account": "personal",
  "accounts": {
    "personal": {
      "email": "you@gmail.com",
      "token_file": "tokens/personal.json",
      "allowed_recipients": ["you@gmail.com"]
    },
    "work": {
      "email": "you@yourcompany.com",
      "token_file": "tokens/work.json",
      "allowed_recipients": []
    }
  }
}

Step 6: Sign in to each account once

.venv/bin/python auth.py personal
.venv/bin/python auth.py work

A browser tab opens for each command. Sign in as the matching account and approve Send email on your behalf. The refresh tokens are saved to tokens/, which git ignores and which only your user can read. To revoke access later, go to https://myaccount.google.com/permissions.

Step 7: Connect it to Claude

Claude Code:

claude mcp add gmail-multi -- /full/path/to/gmail-mcp/.venv/bin/python /full/path/to/gmail-mcp/server.py

Claude Desktop: add this to claude_desktop_config.json (Settings → Developer → Edit Config), then restart the app:

{
  "mcpServers": {
    "gmail-multi": {
      "command": "/full/path/to/gmail-mcp/.venv/bin/python",
      "args": ["/full/path/to/gmail-mcp/server.py"]
    }
  }
}

Step 8: Test it

Ask Claude:

Use gmail-multi to list my accounts, then send a test email from my personal account to me with the subject “Wrist Log test”.

Check your personal inbox. Then try the same from work.

Step 9: Route the weekly health report

Update the Sunday 8:54 a.m. scheduled task’s prompt so it ends with something like this:

…then send the report with gmail-multi send_email, account: "personal", to: "you@gmail.com", using the HTML version of the report as html and a plain-text summary as body.

Where the task runs matters. This is a local stdio server, so it’s only reachable from Claude running on the same computer (Claude Desktop or Claude Code there). A scheduled task that runs in the cloud can’t reach it. For a cloud task, the simplest option is to connect the built-in Gmail connector to your personal account, since it sends from whichever account it’s connected to. Use this server when you want to choose between accounts from your own machine.

Files

File Purpose
server.py The MCP server (stdio) with the list_accounts and send_email tools.
auth.py One-time browser sign-in for each account.
gmail_accounts.py Loads the config, refreshes tokens, builds MIME messages, enforces the allowlist.
accounts.example.json Template for accounts.json.

You can set the environment variables GMAIL_MCP_CONFIG and GMAIL_MCP_CLIENT_SECRET to keep the config and client secret somewhere other than this folder.

Troubleshooting