Mailpit vs smtp4dev
Mailpit
mailpit.axllent.orgsmtp4dev
github.comSide by side
| Figure | Mailpit | smtp4dev |
|---|---|---|
| Price from | Free | — |
| Free plan | Yes | — |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 0 |
| Spec score · Email Testing Software | 8.6 (#6) | 7.2 (#23) |
| Deployment | Mailpit runs as a single binary or multi-architecture Docker image, and publishes static binaries for Windows, Linux, and Mac. | Installation options include winget, Docker/OCI images, a .NET global tool, and GitHub release downloads. |
| Message inspection | The web UI can display formatted HTML, highlighted HTML source, text, headers, raw source, and MIME attachments with image thumbnails. | Features include SMTP session logs, multipart MIME inspection, HTML rendering, validation, and compatibility reports. |
| Purpose | Mailpit is an open-source utility for testing emails and SMTP delivery, with a local SMTP server, web interface, and integration-testing API. | smtp4dev is a fake SMTP server for development and testing, letting developers test email without sending it to real customers. |
Plans
In their own words
Mailpit
Mailpit is a free, open-source tool for checking email content and SMTP delivery without sending messages to real addresses. It runs a local SMTP server alongside a web interface and REST API, and is available for Linux, macOS, Windows, Docker, and self-hosted deployment. The interface displays formatted HTML, source, text, headers, raw messages, and MIME attachments with image thumbnails. Checks include HTML and link testing, message screenshots, and optional SpamAssassin scoring. The API can access, search, send, delete, tag, and release messages; messages can also be relayed, forwarded, or used to trigger configurable SMTP errors. Mailpit can send message-summary webhooks and offers a Cypress package for integration tests. The web UI and API can use HTTPS and basic authentication; SMTP supports optional authentication and TLS. By default, SMTP listens on port 1025 without encryption or authentication. Mailpit keeps the most recent 500 messages by default.