Disposable inboxes for AI agents and CI: catch the verification email, read the OTP or link.
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.
npm install -g @mailsink/mcp
Or run via npx without installing:
npx @mailsink/mcp
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:
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.
claude mcp add mailsink -- npx -y @mailsink/mcp
Add to the mcpServers section of the client's config file:
{
"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.
| 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. |
> 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.
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.https://github.com/heocoi/mailsink/tree/main/mcp
MIT — see LICENSE.
Source-derived launch command. Check the maintainer’s required arguments and credentials before running:
npx -y @mailsink/mcpMerge this template into ~/Library/Application Support/Claude/claude_desktop_config.json. Keep existing servers. Add any arguments, credentials, and permissions required by the maintainer; this template has not been install-tested.
{
"mcpServers": {
"io-github-heocoi-mailsink": {
"command": "npx",
"args": [
"-y",
"@mailsink/mcp"
]
}
}
}Restart Claude Desktop completely for changes to take effect. Confirm the server appears connected in the client’s tool list, then try a read-only example from its documentation.
Claude Desktop setup reference@mailsink/mcpnpmio.github.heocoi/mailsink works with any MCP-compatible client. Copy the config snippet from the Configuration section above and add it to the file shown for your client, then restart the application.
~/Library/Application Support/Claude/claude_desktop_config.jsonRestart Claude Desktop completely for changes to take effect.~/.cursor/mcp.jsonRestart Cursor for changes to take effect..vscode/mcp.jsonReload VS Code window for changes to take effect.~/.codeium/windsurf/mcp_config.jsonRestart Windsurf for changes to take effect..mcp.jsonSave at the project root, then start Claude Code in that project and review the MCP server approval prompt. Keep real credentials out of shared files.