EmptyInbox

EmptyInbox is a disposable-email service for developers and AI agents that need a separate receiving address for each task. It is best suited to automated verification and test workflows built around REST or MCP, rather than ordinary correspondence or permanent records. Its focused automation tooling is useful, but seven-day deletion and credit-based inbox creation demand careful workflow planning.

Overview

Each task or agent run can receive a new disposable address, after which a workflow polls for mail or uses MCP’s wait_for_message flow. That makes verification-code retrieval more predictable than sharing one address across unrelated runs. Receiving, listing and reading messages do not consume credits; creating an inbox does, so address churn—not message volume—is the main usage cost.

Messages are automatically deleted after seven days. That is long enough for many signup and testing flows, but unsuitable when a team needs a durable message archive or audit history. EmptyInbox receives mail only: there is no sending endpoint and no SMTP access, ruling it out for two-way workflows.

The privacy policy says account email addresses and passwords are not stored, and data is not sold or shared for advertising. Account creation is still associated with network data: the service records the network address and identified client software for every creation attempt, retaining the address linked to a surviving account while it exists.

Key features

• REST API and MCP server: API clients can create and read inboxes directly, while MCP-compatible agents can wait for incoming mail instead of implementing repeated polling. This is particularly useful for autonomous verification steps.
• Extracted codes and links: The passkey-protected web inbox places detected verification codes and links alongside messages, reducing the work of parsing common sign-up emails.
• Automation guidance: Guides cover Playwright, Cypress, n8n and LangChain workflows. Integration options also include OpenAI GPT Actions, CrewAI and OpenAPI-compatible frameworks, giving developers several established ways to connect email receipt to an agent pipeline.
• Open-source project: The MIT-licensed project is built and maintained by Blockonomics. Questions are directed to GitHub issues, which suits developer-led support but is less formal than a dedicated service desk.
• Seven-day retention: Automatic deletion limits exposure and storage, while also making the service unsuitable for records that must remain accessible beyond a week.

Pricing

EmptyInbox uses a free plan plus one-time credit top-ups. Credits are consumed when an inbox is created, never expire on paid plans, and purchases are non-refundable. There are no separate charges for receiving, listing or reading messages.

Plan	Price and terms	Included	Best for
Free	0.00 USD, forever free	5 inbox credits, REST API and MCP access, email polling, seven-day message deletion	Occasional tests and evaluating an integration
Top-up — Micro	1.00 USD once, Bitcoin or USDT	10 credits; $0.10 per inbox	Small bursts after the free allocation
Top-up — Starter	5.00 USD once, Bitcoin or USDT	50 credits; $0.10 per inbox	Regular development and test runs
Top-up — Standard	15.00 USD once, Bitcoin or USDT	200 credits; $0.075 per inbox	Higher-volume automation seeking a lower unit cost
Top-up — Bulk	40.00 USD once, Bitcoin or USDT	750 credits; $0.053 per inbox	Large test suites or frequent agent runs

The free tier is genuinely useful for low-volume work, but five creations disappear quickly in parallel testing. Bulk pricing lowers the per-inbox cost, yet the one-time, non-refundable structure rewards teams that can forecast demand; it is less forgiving when a project changes direction.

Platforms

EmptyInbox is available through its web inbox and supports Linux and API-based use. REST and MCP access make it practical in server-side and agent environments, while the passkey web interface provides a manual fallback for inspecting messages.

Who it's for

Choose EmptyInbox for developers automating account verification, browser tests or agent tasks that need isolated receiving addresses. It is also a sensible fit for teams already using MCP, LangChain, CrewAI, OpenAI GPT Actions or OpenAPI tooling. Look elsewhere if you need to send mail, retain messages longer than seven days, keep a searchable history, or avoid metering every new inbox.

Pros and cons

Pros

• Automation-first API and MCP support: Fits programmatic and agent-driven verification flows.
• Free message operations: Polling and reading do not add per-message fees.
• Useful extraction and passkey access: Codes and links are surfaced in the web inbox without abandoning developer workflows.
• Credits never expire: Paid capacity can be saved for intermittent projects.

Cons

• Receive-only: No sending endpoint or SMTP credentials means no reply or outbound-mail workflows.
• Seven-day deletion: Messages cannot serve as long-term records.
• Credit per inbox: High churn can exhaust quotas even when few messages arrive.
• Non-refundable top-ups and network logging: Forecast usage carefully and account for the creation metadata retained by the service.

Alternatives

For a broader comparison of disposable inbox products, see Temporary Email Services.

• SecureTempMail is the better choice when you need up to 30-day retention, private domains, attachment downloads and inbox search, especially across desktop platforms and extensions.
• Temp-Mail.org suits users who want Android or iOS access and a consumer-oriented service; its free messages last only 1–2 hours, while premium is billed monthly.
• 10 Minute Mail is preferable for a quick, browser-based address that expires after 10 minutes and can be extended briefly.
• 1SecMail is worth considering for mobile, extension and API access with saved-message and attachment features.
• EmailOnDeck is an ad-supported option for one private address at a time, with logs securely wiped.
• TempMailo fits users wanting save-and-restore inboxes and reply relay on a free service.
• Getnada provides browser-based guest and member inboxes, with an API available on the service.
• Mail.cx is the alternative for web inboxes with one-hour free retention or paid custom domains and API access.

Verdict

EmptyInbox is a strong choice for developers and AI-agent builders who need repeatable, task-specific inbound verification through REST or MCP. Its free starting tier, expiring credits and bulk discounts keep costs understandable, but receive-only operation, seven-day retention and per-inbox charging are decisive limitations. Choose it for short-lived automated workflows; choose another service when email must be sent, preserved or managed as a conventional mailbox.