e2a

e2a is an open-source email API for applications and AI agents, from TokenCanopy. Its hosted MCP server gives your agent its own two-way email address, on the shared agents.e2a.dev domain or on a domain you verify, so it can send, receive and reply in-thread. You can also hold its outgoing mail for a person to approve before it leaves. What you can do with it - Read the inbox, fetch full messages and attachments, and label, trash or restore mail (list_messages, get_message, get_attachment, update_message_labels, delete_message, restore_message). - Send new email, reply in the same thread and forward messages, now or at a set time (send_message, reply_to_message, forward_message; scheduled sending is in beta). - Review held mail: list what's waiting, then approve, edit or reject it (list_reviews, get_review, approve_review, reject_review). Only an account-level sign-in can approve, so an agent can't approve its own mail. - Set up inboxes and domains: create agent inboxes, register a custom sending domain and get its DNS records, and mint agent-scoped API keys (create_agent, register_domain, create_api_key). - Manage contacts, outreach, email templates and suppression lists (several of these are in beta). How it connects It's a hosted MCP server at https://api.e2a.dev/mcp. In an agent that supports OAuth connectors, add the address and sign in to e2a in your browser; there's no key to paste. For programmatic use, send an e2a API key from the dashboard as a Bearer token instead. e2a's docs show Claude Desktop, Cursor, Cline, Google ADK, LangChain and the OpenAI Agents SDK, and it also offers a Claude Code plugin. Good to know - The tools you get depend on the sign-in: an agent-scoped credential sees the inbox tools for its one agent, and an account-scoped one also sees the admin and review tools. - Every inbound message carries SPF, DKIM and DMARC results, and optional screening can flag prompt injection and hold suspicious mail for review. - Human approval is opt-in per agent. Held mail waits until a person approves it from the dashboard, the MCP tools, the API or an emailed link. - On the hosted service, an account can mail its own verified address and its own agent inboxes straight away. Mailing anyone else from the shared domain needs a one-time approval from e2a, which you can request with request_sending_access. - There's a free plan, and paid plans raise the limits. e2a is Apache-2.0 and can be self-hosted.

• “Create an email agent and listen for new mail.”

  1. create_agent
  2. list_messages
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• “Reply to Dana's thread and hold it for my approval.”

  1. reply_to_message
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• “Reply to the latest unread email politely.”

  1. list_messages