@mailsink/mcp

Name: Mailsink
Author: heocoi

Model Context Protocol server for MailSink — programmatic temporary email inboxes for AI agents and test automation.

Gives your agent eight typed tools for provisioning disposable addresses, waiting on signup emails, extracting OTP codes and magic links, and cleaning up after itself. Works in Claude Code, Claude Desktop, Cursor, Windsurf, and any other MCP-aware client.

Install

bash

npm install -g @mailsink/mcp

Or run via npx without installing:

bash

npx @mailsink/mcp

Get an API key

Sign in at https://mailsink.dev/app with GitHub.
Copy the key from the one-time reveal. Store it in your password manager or .env.
Export it so the MCP server can read it:
bash
```
export MAILSINK_API_KEY="msk_..."
```

Free tier is 50 inboxes/month and includes MCP. Pro ($15/mo) and Team ($49/mo) lift the inbox cap, raise email size limits, extend TTL, and bump request rates. See pricing.

Configure your client

Claude Code

bash

claude mcp add mailsink -- npx -y @mailsink/mcp

Claude Desktop / Cursor / Windsurf

Add to the mcpServers section of the client's config file:

json

{
  "mcpServers": {
    "mailsink": {
      "command": "npx",
      "args": ["-y", "@mailsink/mcp"],
      "env": {
        "MAILSINK_API_KEY": "msk_..."
      }
    }
  }
}

Restart the client. You should see the mailsink server listed with its eight tools.

Tools

Tool	Purpose
`create_inbox`	Provision a throwaway address. Returns `email`, `id`, `expires_at`.
`list_inboxes`	List active inboxes on the account.
`wait_for_email`	Block up to `timeout` seconds (max 120) for any email to arrive.
`get_verification_code`	Extract the most recent OTP from the inbox (polls until found or timeout).
`get_verification_link`	Extract the most recent magic link.
`list_messages`	Summaries of all messages in an inbox.
`get_message`	Full content of a specific message by ID.
`delete_inbox`	Burn an inbox immediately.

Example agent flow

> Sign me up for Figma, capture the verification code, confirm, and
> tell me the plan once you're in.

[agent invokes]
  create_inbox()                                → agent@codenotify.net
  [agent fills the Figma signup form with that address]
  wait_for_email(inbox_id)                      → blocks 30s…
                                                → returns email + OTP
  [agent types the OTP into the Figma form]
  delete_inbox(inbox_id)                        → cleanup

No webhook plumbing. No IMAP credentials. No parsing MIME.

Environment variables

MAILSINK_API_KEY (required) — your account's API key.
MAILSINK_API_URL (optional, default https://api.mailsink.dev) — override for self-hosted or dev API.