Yahoo Mail MCP Server

MCP server exposing Yahoo Mail (via IMAP) as tools for Claude: list folders, search/read emails, manage flags and folders.

Setup

1. Generate a Yahoo App Password: Yahoo Account Security page -> "Generate app password". A regular account password will not work if 2FA is enabled.

2. Copy .env.example to .env and fill in your credentials:

   cp .env.example .env

3. Install dependencies (managed by devenv/bun):

   bun install

4. Run the server directly to confirm it authenticates without error:

   bun run src/index.ts

   Ctrl-C to stop. If you see an AuthenticationFailure-related error, double check YAHOO_APP_PASSWORD is an app password, not your account password.

Related MCP server: Babushka Email MCP

Registering with Claude Code

claude mcp add yahoo-mail bun run /home/bhuvan/Developer/yahoo-mail-mcp/src/index.ts

Or add to .mcp.json:

{
  "mcpServers": {
    "yahoo-mail": {
      "command": "bun",
      "args": ["run", "/home/bhuvan/Developer/yahoo-mail-mcp/src/index.ts"],
      "env": {
        "YAHOO_EMAIL": "you@yahoo.com",
        "YAHOO_APP_PASSWORD": "xxxxxxxxxxxxxxxx"
      }
    }
  }
}

Registering with Claude Desktop

Add to claude_desktop_config.json (Settings -> Developer -> Edit Config):

{
  "mcpServers": {
    "yahoo-mail": {
      "command": "bunx",
      "args": ["github:boo1-boo1/yahoo-mail-mcp"],
      "env": {
        "YAHOO_EMAIL": "you@yahoo.com",
        "YAHOO_APP_PASSWORD": "xxxxxxxxxxxxxxxx"
      }
    }
  }
}

Or, running from a local clone instead of GitHub:

{
  "mcpServers": {
    "yahoo-mail": {
      "command": "bun",
      "args": ["run", "/home/bhuvan/Developer/yahoo-mail-mcp/src/index.ts"],
      "env": {
        "YAHOO_EMAIL": "you@yahoo.com",
        "YAHOO_APP_PASSWORD": "xxxxxxxxxxxxxxxx"
      }
    }
  }
}

Restart Claude Desktop after editing the config.

Tools

• list_folders - list all mailboxes.

• search_emails - search a folder by sender, subject, free text, date range, unread/flagged status. Returns lightweight summaries (newest first).

• get_email - fetch full content (headers, text/HTML body, attachment metadata) of one message by folder + UID.

• get_attachment - download one attachment's content (base64) by folder, UID, and partId (from get_email).

• mark_read - mark a message read/unread.

• flag_email - flag/unflag (star) a message.

• move_email - move a message to another folder.

• delete_email - soft delete (move to Trash) by default; permanent: true expunges immediately and cannot be undone.

All operations identify messages by IMAP UID (stable across sessions), not sequence number.