Mails.ai — Agent Email

Official

by mails

A real inbox for AI agents: send, receive and thread email, behind a prompt-injection firewall.

A Model Context Protocol (MCP) server that provides a “real inbox for AI agents,” enabling sending, receiving, and threading of email. The service operates “behind a prompt-injection firewall,” intended to protect agent interactions involving email content.

🛠️ Key Features

Send email for AI agents
Receive email for AI agents
Thread email conversations
Prompt-injection firewall for email-related interactions

🚀 Use Cases

Building AI agents that need real inbound and outbound email
Maintaining email conversation threads for agent context

⚡ Developer Benefits

Email integration for agent workflows (send/receive/thread)
Additional protection via a prompt-injection firewall

⚠️ Limitations

Specific implementation details (tools, APIs, or interfaces) are not provided in the available data

Install

Configuration

Environment variables

MAILS_API_KEYrequiredsecret

Your mails.ai API key. Use an mk_test_ key to run against the sandbox or an mk_live_ key to send real mail. Free key at https://mails.ai

MAILS_BASE_URL

Override the API base URL. Defaults to the hosted mails.ai API; only needed for staging or self-hosted deployments.

Add to VS Code Add to Cursor

claude_desktop_config.json

json

{
  "mcpServers": {
    "agent-email": {
      "command": "npx",
      "args": [
        "-y",
        "@mailsai/mcp-server@0.2.12"
      ],
      "env": {
        "MAILS_API_KEY": "<YOUR_MAILS_API_KEY>",
        "MAILS_BASE_URL": "<YOUR_MAILS_BASE_URL>"
      }
    }
  }
}