EmptyInbox vs Mail.cx
EmptyInbox
emptyinbox.meMail.cx
mail.cxSide by side
| Figure | EmptyInbox | Mail.cx |
|---|---|---|
| Price from | Free | $0.82/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Linux | Yes | — |
| API | Yes | Yes |
| Plans published | 5 | 4 |
| Spec score · Temporary email services | 8.4 (#12) | 9.1 (#4) |
| Spec score · Temporary Email Services | 8.4 (#9) | 8.9 (#6) |
| Inbox creation | A new disposable email address can be created for each task or agent run. | Users can pick a username or generate one randomly, and the web inbox is available without signup. |
| Privacy | The privacy policy says the service does not store email addresses or passwords for accounts, and does not sell or share data for advertising. | The privacy policy says inbox content, account email, and API tokens are not sold, rented, or shared with advertisers or other third parties. |
| Retention | Messages are deleted automatically after seven days. | Mail is kept for 1 hour on Free and 72 hours on Pro, then automatically deleted. |
| Service limitation | EmptyInbox receives email only and has no email-sending endpoint or SMTP credentials. | The terms say the service does not guarantee message retention or recovery and should not be relied on for critical, sensitive, or business-essential communications. |
Plans
EmptyInbox
- FreeFree
- Top-up — Micro$1, paid once
- Top-up — Starter$5, paid once
- Top-up — Standard$15, paid once
- Top-up — Bulk$40, paid once
In their own words
EmptyInbox
EmptyInbox provides disposable email inboxes for AI agents and developers through a REST API, an MCP server and a web inbox. A new address can be created for each task or agent run. Messages can be polled, or received through the MCP wait_for_message flow, which can extract verification codes. The web inbox uses passkey sign-in and displays extracted codes and links alongside messages. Each inbox creation uses one credit; receiving, listing and reading messages are free. Messages are deleted automatically after seven days. EmptyInbox receives email only and has no sending endpoint or SMTP credentials. Listed integrations include MCP-compatible agents, OpenAI GPT Actions, LangChain, CrewAI and OpenAPI-compatible frameworks; workflow guides cover Playwright, Cypress, n8n and LangChain. The free plan includes five inbox credits and REST API and MCP access. One-time top-ups start at 1.00 USD for 10 credits, payable by Bitcoin or USDT. The project is open source under the MIT license, and questions go through GitHub issues.
Mail.cx
Mail.cx provides short-lived inboxes for developers, QA teams, and product teams checking account verification, transactional messages, notification pipelines, or application integrations. It only receives email; it does not send it. A web inbox can be opened without signup by choosing a username or generating one, and server-sent events can push arriving mail to the browser. Its REST API supports long-polling, retrieval of parsed or raw email, attachment downloads, and event delivery. API use is limited to 10 requests per second per token; long-polling allows one concurrent wait per token and 10 per address. Free messages are automatically deleted after one hour, while Pro messages are retained for 72 hours. The Free plan is free, and Pro is $9.90 a year. A separate pricing note lists paid plans from $4/mo. Mail.cx says connections use TLS and that passwords and API tokens are stored as hashes. Its terms caution that message retention and recovery are not guaranteed, and advise against relying on the service for critical, sensitive, or business-essential communications.