Inbucket receives email from test applications and makes the captured messages available through a web interface or API. Developers can inspect a password-reset link, notification or generated message without delivering it to a real mailbox. It is useful in development and automated tests because mailboxes can be created as messages arrive. Keep that convenience private: captured messages can contain credentials or personal data even when the sender is a test environment.
Current guidance
Its upstream README documents built-in SMTP, HTTP, POP3 and storage, without an external database requirement. This makes it useful for application tests that need to inspect an email without delivering it to a real recipient.
Configure test applications to send to a dedicated internal SMTP endpoint and restrict access to the message viewer and API. Captured password-reset links and test fixtures can contain usable credentials or personal information, so mailbox convenience should not become a public catch-all service. Decide whether test messages should survive restarts or be cleared between runs.
The upstream image tags distinguish released builds from the potentially unstable edge branch. Pin the intended release and check retention and storage settings rather than copying a floating development tag. In automated tests, correlate messages with a unique test address and verify recipients and content through the API. Keep outbound mail delivery and production email security separate from this test harness; this review did not run an SMTP integration test.
Historical upstream link check · 2026-10-09
The recorded upstream address redirects to https://inbucket.org/ and returned HTTP 200 on 2026-10-09. Link availability does not certify the historical installation instructions or current security support.
Website availability is separate from project, chart and image support. Use the current guidance and primary sources on this page to assess the distribution.
Historical Kubedex content
Preserved for context. Commands, versions, prices and results below reflect the original research.
Inbucket is an email testing application; it will accept messages for any email address and make them available to view via a web interface. If you’ve ever used mailinator.com, you already have a good idea of what Inbucket does. The benefit of Inbucket is that it is an application instead of a hosted service; you may run it on your own private network, or even your desktop.
Inbucket allows web developers, software engineers, and system administrators to quickly see the emailed output of their applications. No per-account setup is required! Mailboxes are created on the fly as mail is received for them, and no password is required to browse the content of the mailboxes.
Inbucket has built-in SMTP and POP3 servers which store incoming mail as flat files on disk – no external SMTP or database daemons required.
Inbucket was written in Google Go and is open source software released under the MIT License.
Mail features
- Receive and store E/SMTP messages
- Purge messages after a configurable amount of time
- Enforce a cap on the number of messages per mailbox by deleting older messages
- Optional load test mode; no messages are ever written to disk
- Configurable load test domain; messages addressed to it are never written to disk
- Access mail via embedded POP3 server
Web-interface features
- List messages in a mailbox
- Displays text content of a particular message
- Displays source of a message (headers + body text)
- Displays HTML version of a message (in a new window)
- List MIME attachments with buttons to display or download
- Delete a message
- Monitor – a real-time display of received messages
- RESTful: REST API Docs
Why Inbucket?
Need to test your web apps outbound emails with Mailinator but stuck behind a firewall? Want to keep the new application you are developing secret until it’s time to release it? Need to validate that emails go out as part of your integration test suite? Want to send a link to a coworker demonstrating an email without giving them your Gmail password? Need to load test your application without melting your corporate Exchange server? Want to use production data in your test environment without the risk of test messages leaking to an end user? Need to preview emails in multiple desktop email clients? Use Inbucket!
Sources & further reading
Spotted something that needs another look?
Help improve this page →