Spare Mailbox

Spare Mailbox gives you a throwaway email address instantly — no signup, no password, no cookie wall. Open the site, get an address, receive mail in seconds, and keep spam out of your real inbox.

What makes it useful beyond the usual temp-mail site:

• Free public API. Create an inbox, list messages, and fetch a message body over plain HTTP. No account needed to start, so you can wire it into signup tests, QA runs, and CI without ceremony.

• MCP server for coding agents. Point Claude, Cursor, or any MCP client at https://mcp.sparemailbox.com/mcp and your agent can create its own disposable inbox and read the confirmation email itself — no copy-pasting verification codes between a browser and a chat window.

• Attachments are kept, not dropped, so you can actually test receipts, invoices, and exports.

• HTML is sandboxed before it renders, so tracking pixels and remote content don't phone home.

• Available in 19 languages.

Built for developers testing signup and password-reset flows, QA engineers who need a fresh address per test run, and anyone who just doesn't want to hand over their real address to download a PDF.

Runs on Cloudflare Workers, D1, and R2 — fast everywhere, and cheap enough to keep the core free.