InboxKitten
InboxKitten is a free, open-source disposable email service for testing and other non-critical messages.
What InboxKitten is
InboxKitten is a free, open-source disposable email service for testing and other non-critical messages. Users can create temporary inboxes instead of sharing a real email address, which can help avoid spam. It is intended for checking signup flows and email notifications in web applications. The project provides a web interface, an API, and a command-line tool for API interaction. InboxKitten.com inboxes are public, and messages disappear after several hours; Mailgun setup instructions state that received mail is stored for three days. The service connects to Mailgun for incoming email. Users can clone and run their own instance through Docker, serverless Firebase or Cloudflare, localhost, or custom deployments, with Firebase and Mailgun accounts required for self-hosting. The project uses the MIT license and supports custom addresses, custom domains, and API access.
Good
- Free plan available
- Open-source project under MIT license
- Web, API, and command-line access
- Supports custom addresses and domains
- Offers Docker and serverless deployment paths
Watch out
- Public inboxes are unsuitable for private mail
- Messages delete after several hours
- Self-hosting requires Firebase and Mailgun accounts
- Mail storage is stated as three days
Who it suits
It suits developers testing registration flows or notifications and people needing disposable addresses for non-critical email. Self-hosting options fit users comfortable deploying web, API, and mail components.
Verdict
InboxKitten is a practical disposable inbox for testing and low-stakes messages. Its public, short-lived mail means important or private correspondence belongs elsewhere.
Plans and prices
From InboxKitten's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Self-Host | — | Deploy your own instance · Requires Firebase and Mailgun accounts · *per month |
The facts
Each one read from InboxKitten's own pages, with the date it was checked.
What it does
- Abuse prevention
- The site says it blocks no-reply@google to prevent abuse.checked 8 Oct 2026
- Components
- The repository describes an API, a web UI, and a command-line tool for interacting with the API.checked 8 Oct 2026
- Data retention
- The repository’s Mailgun setup instructions say received mail is stored for 3 days.checked 8 Oct 2026
- Deployment options
- The repository documents Docker, serverless Firebase or Cloudflare, and localhost or custom deployments.checked 8 Oct 2026
- License
- The GitHub repository lists the project under the MIT license.checked 8 Oct 2026
- Mail provider
- The repository says InboxKitten connects to Mailgun to receive email.checked 8 Oct 2026
- Privacy limitation
- InboxKitten.com inboxes are public, and emails auto-delete after several hours; the page says Mailgun’s stated retention is 3 days.checked 8 Oct 2026
- Product
- InboxKitten is an open-source disposable email service.checked 8 Oct 2026
- Self-hosting
- The maker says users can clone and deploy their own InboxKitten instance.checked 8 Oct 2026
- Spam avoidance
- The service is intended to help avoid spam by letting users avoid sharing their real email address.checked 8 Oct 2026
- Testing
- The site describes using InboxKitten to test signup flows and email notifications in web applications.checked 8 Oct 2026
- Use case
- The site recommends using InboxKitten for testing or non-critical emails.checked 8 Oct 2026
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