EmptyInbox

EmptyInbox is a disposable-email utility for developers and AI agents that need a separate incoming address for each automated task. It is best for verification and testing workflows built around REST, MCP, or a web inbox, rather than ordinary correspondence. Its credit-per-inbox pricing and receive-only operation should shape the decision.

Overview

A workflow can create a fresh address for an agent run, then poll for mail or use MCP's wait_for_message flow to wait for a message and extract a verification code. That task-specific model limits cross-run contamination and fits automated sign-up or test sequences, but it is less suitable when an address must remain a durable mailbox. Receiving, listing, and reading messages are free; creating each inbox consumes one credit, so address volume—not message volume—is the main usage cost.

Messages are deleted automatically after seven days. That is enough time for many verification flows, but it rules out using EmptyInbox as a long-term archive or audit record. The web inbox uses passkey sign-in and places extracted codes and links alongside messages, which gives people a practical fallback when an automation needs visual checking.

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, and keeps the address linked to a surviving account while that account exists.

Key features

• REST API and MCP server: REST supports programmatic inbox creation and retrieval, while MCP-compatible agents can wait for incoming mail instead of implementing their own polling loop. This is a strong fit for agent orchestration and scripted verification.
• Disposable addresses per run: New inboxes can be allocated to individual tasks or agent executions. The isolation is useful in parallel workflows, though every new inbox spends a credit.
• Code and link extraction: The web inbox displays extracted verification codes and links with messages, reducing the effort needed to identify the value an automated flow is waiting for.
• Automation integrations and guides: The maker points to MCP-compatible agents, OpenAI GPT Actions, LangChain, CrewAI, and OpenAPI-compatible frameworks, with workflow guides for Playwright, Cypress, n8n, and LangChain.
• Receive-only service: There is no email-sending endpoint and no SMTP credentials. Choose it for inbound verification, not for reply, notification, or two-way mail workflows.
• Open-source support model: The project is MIT-licensed and questions are directed to a GitHub issue. That suits teams comfortable using an issue tracker rather than expecting a conventional support desk.

Pricing

The free plan costs 0.00 USD and is free forever. It includes five inbox credits, REST API and MCP access, email polling, and seven-day automatic message deletion. It is appropriate for experiments, small test suites, and occasional agent runs; five creations will be exhausted quickly by repeated or parallel testing.

Paid access is sold as one-time credit top-ups, with credits that never expire. Micro costs 1.00 USD once for 10 credits ($0.10 per inbox), while Starter costs 5.00 USD once for 50 credits at the same per-inbox rate. Standard costs 15.00 USD once for 200 credits ($0.075 per inbox), and Bulk costs 40.00 USD once for 750 credits ($0.053 per inbox). Standard and Bulk are the sensible choices for recurring automation because they lower the creation cost; Micro and Starter suit smaller bursts without a recurring subscription. Quota purchases are non-refundable, and payment is by Bitcoin or USDT, which may be a constraint for buyers requiring card or invoice billing.

Platforms

EmptyInbox supports API access, Linux, and the web. The API and MCP interfaces target developer workflows, while the passkey-protected web inbox provides a browser-based way to inspect incoming messages.

Who it's for

Choose EmptyInbox for developers building disposable-email steps into Playwright, Cypress, n8n, LangChain, CrewAI, GPT Actions, or other API-compatible automation. It also fits AI-agent runs that need a fresh address and a wait-for-message operation. It is not the right tool for sending mail, preserving messages beyond seven days, or maintaining a conventional long-lived inbox.

Pros and cons

Pros

• Purpose-built automation interfaces: REST and MCP cover both conventional scripts and agent-oriented waiting.
• Free message handling: Listing, receiving, and reading do not consume credits, so traffic after inbox creation is not separately metered.
• Non-expiring top-up credits: Unused paid capacity remains available for later runs instead of requiring a monthly renewal.
• Useful browser fallback: Passkey sign-in plus extracted codes and links helps when an automated flow needs human inspection.

Cons

• Receive only: No sending endpoint or SMTP access excludes two-way email workflows.
• Seven-day deletion: Messages cannot serve as a long-term record.
• Creation-based quota: Every new inbox costs a credit, even though message operations are free.
• Limited free allowance: Five inbox credits make the free tier a short trial for high-volume testing.
• Non-refundable, crypto-only top-ups: Bitcoin or USDT payment and irreversible quota purchases reduce payment flexibility.

Alternatives

See the Temporary Email Services list for a broader comparison. Choose SecureTempMail instead when you need up to 30-day retention, private domains, attachment downloads, inbox history and search, or a wider set of desktop and mobile platforms for its 39.00 USD-per-year Premium plan.

Temp-Mail.org is a better fit for broad mobile and browser access, with free messages retained for 1–2 hours and a paid monthly tier. Pick 10 Minute Mail when a deliberately short, resettable 10-minute address is all you need. 1SecMail is an alternative for users wanting own domains, saved messages, inbox records, and attachment viewing. EmailOnDeck suits ad-supported, one-at-a-time disposable use with logs wiped securely. TempMailo offers save-and-restore inboxes and reply relay. Emailnator is suited to public, no-signup inboxes and up to 100 addresses at once, with messages deleted after 24 hours. EvilMail provides unlimited temporary generation with inbox lifetimes from 10 minutes to 24 hours.

Verdict

EmptyInbox is a strong choice for developers and AI-agent builders who need programmable, task-specific inbound mail through REST or MCP. Its permanent top-up credits, free message operations, and automation-oriented integrations keep recurring verification costs predictable. Look elsewhere if your workflow must send email, retain messages longer than seven days, or avoid credit purchases and crypto-only payment.